PEB2070-P [ETC]
?ISDN Communication Controller? ; ？ ISDN通信控制器？\n
| 型号： | PEB2070-P |
| 厂家： | 
ETC |
| 描述： | ?ISDN Communication Controller?
|
| 文件： | 总168页 (文件大小：775K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
ICs for Communications
ISDN Communication Controller
ICC
PEB 2070
PEF 2070
User’s Manual 01.94
PEB 2070; PEF 2070
Revision History:
01.94
Previous Releases:
06.92
Page
Subjects (changes since last revision)
Update
Data Classification
Maximum Ratings
Maximum ratings are absolute ratings; exceeding only one of these values may cause irrevers-
ible damage to the integrated circuit.
Characteristics
The listed characteristics are ensured over the operating range of the integrated circuit. Typical
characteristics specify mean values expected over the production spread. If not otherwise
specified, typical characteristics apply at T = 25 °C and the given supply voltage.
A
Operating Range
In the operating range the functions given in the circuit description are fulfilled.
For detailed technical information about “Processing Guidelines” and
“Quality Assurance” for ICs, see our “Product Overview”.
Edition 01.94
This edition was realized using the software system FrameMaker®.
Published by Siemens AG, Bereich Halbleiter, Marketing-Kommunikation,
Balanstraße 73, D-81541 München
© Siemens AG 1994. All Rights Reserved.
As far as patents or other rights of third parties are concerned, liability is only assumed for components , not for
applications, processes and circuits implemented within components or assemblies.
The information describes the type of component and shall not be considered as assured characteristics.
Terms of delivery and rights to change design reserved.
For questions on technology, delivery, and prices please contact the Offices of Semiconductor Group in Germany
or the Siemens Companies and Representatives worldwide (see address list).
Due to technical requirements components may contain dangerous substances. For information on the type in
question please contact your nearest Siemens Office, Semiconductor Group.
Siemens AG is an approved CECC manufacturer.
Packing
Please use the recycling operators known to you. We can also help you - get in touch with your nearest sales
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For packing material that is returned to us unsorted or which we are not obliged to accept, we shall have
to invoice you for any costs incurred.
General Information
Table of Contents
Page
1
1.1
1.2
1.3
1.4
1.5
1.5.1
1.5.2
1.5.3
Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Pin Definitions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Logic Symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
System Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
ISDN Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Other Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Microprocessor Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2
2.1
2.2
Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
General Functions and Device Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Serial Interface Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
IOM®-1 Mode (IMS = 0, DIM2 = 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
IOM®-2 Mode (IMS = 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
HDLC Controller Mode (IMS = 0, DIM2 = 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
mP Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
ISDN Oriented Modular (IOM®) Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
SSI (Serial Port A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
SLD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Individual Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Layer-2 Functions for HDLC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.2.1
2.2.2
2.2.3
2.3
2.3.1
2.3.2
2.3.3
2.3.4
2.4
2.4.1
2.4.1.1 Message Transfer Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
2.4.1.2 Protocol Operations (auto mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.4.1.3 Reception of Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
2.4.1.4 Transmission of Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.4.2
2.4.3
2.4.4
2.4.5
2.4.6
2.4.7
2.4.8
B-Channel Switching (IOM®-1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Access to B / IC Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
C/I Channel Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
MONITOR Channel Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Terminal Specific Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Test Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Documentation of the Auto Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
3
Operational Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Microprocessor Interface Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
IOM® Interface Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Interrupt Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Data Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
3.1
3.2
3.3
3.4
3.5
3.5.1
3.5.2
3.5.2.1 HDLC Frame Reception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
3.5.2.2 HDLC Frame Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Semiconductor Group
3
General Information
Table of Contents
Page
4
4.1
Detailed Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
HDLC Operation and Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Receive FIFO RFIFO Read Address 00-1FH . . . . . . . . . . . . . . . . . . . . . . . . 117
Transmit FIFO XFIFO Write Address 00-1FH . . . . . . . . . . . . . . . . . . . . . . . . 117
Interrupt Status Register ISTA Read Address 20H . . . . . . . . . . . . . . . . . . . . . 117
Mask Register MASK Write Address 20H . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Status Register STAR Read Address 2H . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Command Register CMDR Write Address 2H . . . . . . . . . . . . . . . . . . . . . . . . 120
Mode Register MODE Read/Write Address 22H . . . . . . . . . . . . . . . . . . . . . . 121
Timer Register TIMR Read/Write Address 23H . . . . . . . . . . . . . . . . . . . . . . . 124
Extended Interrupt Register EXIR Read Address 24H . . . . . . . . . . . . . . . . . 126
4.1.1
4.1.2
4.1.3
4.1.4
4.1.5
4.1.6
4.1.7
4.1.8
4.1.9
4.1.10 Transmit Address 1 XAD1 Write Address 24H . . . . . . . . . . . . . . . . . . . . . . . 127
4.1.11 Receive Frame Byte Count Low RBCL Read Address 25H . . . . . . . . . . . . . 128
4.1.12 Transmit Address 1 XAD2 Write Address 25H . . . . . . . . . . . . . . . . . . . . . . . 128
4.1.13 Received SAPI Register SAPR Read Address 26H . . . . . . . . . . . . . . . . . . . 129
4.1.14 SAPI1 Register SAP1 Write Address 26H . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
4.1.15 Receive Status Register RSTA Read Address 27H . . . . . . . . . . . . . . . . . . . . . . 130
4.1.16 SAP12 Register SAP2 Write Address 27H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
4.1.17 TEI1 Register 1 TEI1 Write Address 28H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
4.1.18 Receive HDLC Control Register RHCR Read Address 29H . . . . . . . . . . . . . . . . 132
4.1.19 TEI2 Register TEI2 Write Address 29H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
4.1.20 Receive Frame Byte Count High RBCH Read Address 30H . . . . . . . . . . . . . . 134
4.1.21 Status Register 2 STAR2 Read Address 2BH . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
4.2
Special Purpose Registers: IOM-1Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Serial Port Control Register SPCR Read/Write Address 30H . . . . . . . . . . . . . . . 135
Command/Indication Receive Register CIRR Read Address 31H . . . . . . . . . . . 137
Command/Indication Transmit Register CIXR Write Address 31H . . . . . . . . . . . 138
MONITOR Receive Register MOR Read Address 32H . . . . . . . . . . . . . . . . . . . . 139
MONITOR Transmit Register MOX Write Address 32H . . . . . . . . . . . . . . . . . . . 139
SIP Signaling Code Receive SCR Read Address 33H . . . . . . . . . . . . . . . . . . . . 139
SIP Signaling Code Transmit SSCX Write Address 33H . . . . . . . . . . . . . . . . . . 139
SIP Feature Control Read SFCR Read Address 34H . . . . . . . . . . . . . . . . . . . . 140
SIP Feature Control Write SFCW Write Address 34H . . . . . . . . . . . . . . . . . . . . . 140
4.2.1
4.2.2
4.2.3
4.2.4
4.2.5
4.2.6
4.2.7
4.2.8
4.2.9
4.2.10 Channel Register 1 C1R Read/Write Address 35H . . . . . . . . . . . . . . . . . . . . . . . 140
4.2.11 Channel Register 2 C2R ead/Write Address 36H . . . . . . . . . . . . . . . . . . . . . . . . 140
4.2.12 B1 Channel Register B1CR Read Address 37H . . . . . . . . . . . . . . . . . . . . . . . . . 141
4.2.13 Synchronous Transfer Control Register STCR Write Address 37H . . . . . . . . . . 141
4.2.14 B2 Channel Register B2CR Read Address 38H . . . . . . . . . . . . . . . . . . . . . . . . . 142
4.2.15 Additional Feature Register 1 ADF1 Write Address 38H . . . . . . . . . . . . . . . . . . 142
4.2.16 Additional Feature Register 2 ADF2 Read/Write Address 39H . . . . . . . . . . . . . . 143
Semiconductor Group
4
General Information
Table of Contents
Page
4.3
Special Purpose Registers: IOM-2 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Serial Port Control Register SPCR Read/Write Address 30H . . . . . . . . . . . . . . . 144
Command/Indication Receive 0 CIR0 Read Address 31H . . . . . . . . . . . . . . . . . 146
Command/Indication Transmit 0 CIX0 Write Address 31H . . . . . . . . . . . . . . . . . 146
MONITOR Receive Channel 0 MOR0 Read Address 32H . . . . . . . . . . . . . . . . . 147
MONITOR Transmit Channel 0 MOX0 Write Address 32H . . . . . . . . . . . . . . . . . 148
Command/Indication Receive 1 CIR1 Read Address 33H . . . . . . . . . . . . . . . . . 148
Command/Indication Transmit 1 CIX1 Write Address 33H . . . . . . . . . . . . . . . . . 148
MONITOR Receive Channel 1 MOR1 Read Address 34H . . . . . . . . . . . . . . . . . 149
Channel Register 1 C1R Read/Write Address 35H . . . . . . . . . . . . . . . . . . . . . . . 149
4.3.1
4.3.2
4.3.3
4.3.4
4.3.5
4.3.6
4.3.7
4.3.8
4.3.9
5
6
Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Package Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Figure 24a until figure 26d are CCITT recommendations for comparison.
IOM®, IOM®-1, IOM®-2, SICOFI®, SICOFI®-2, SICOFI®-4, SICOFI®-4µC, SLICOFI®, ARCOFI® , ARCOFI®-BA, ARCOFI®-SP,
EPIC®-1, EPIC®-S, ELIC®, IPAT®-2, ITAC®, ISAC®-S, ISAC®-S TE, ISAC®-P, ISAC®-P TE, IDEC®, SICAT®, OCTAT®-P,
QUAT®-S are registered trademarks of Siemens AG.
MUSAC™-A, FALC™54, IWE™, SARE™, UTPT™, ASM™, ASP™ are trademarks of Siemens AG.
Purchase of Siemens I2C components conveys a license under the Philips’ I2C patent to use the components in the I2C-system
provided the system conforms to the I2C specifications defined by Philips. Copyright Philips 1983.
Semiconductor Group
5
General Information
Introduction
The transmission and protocol functions in an ISDN basis access can
all be implemented
be
using the CMOS circuits of the ISDN Oriented Modular (IOM®) chip set. While three chips, the
S Bus interface Circuit SBC (PEB 2080), the ISDN Echo Cancellation circuit IEC (PEB 2090)
and the ISDN Burst Controller IBC (PEB 2095) perform the transmission functions in different
applications (S and U interface), the ISDN Communication Controller ICC (PEB 2070) acts as
the D-channel-link-access protocol controller.
The IOM® architecture makes possible a wide range of configurations for the Basic Access,
using the basic devices. These configurations essentially differ in the implementation of the
layer-1 OSI functions, while the layer-2 functions are provided by the ICC for all configurations.
In addition to that, the PEB 2070 provides the interface to B-channel sources in the terminal
and to a peripheral board controller (PEB 2050, 51, 52 etc.) at the exchange.
The HDLC packets of the ISDN D channel are handled by the ICC which transfers them to the
associated microcontroller. The ICC has on-chip buffer memories (64 bytes per direction) for
the temporary storage of data packets. Because of the overlapping I/O operations the
maximum length of the D-channel packets is not limited. In one of its operating modes the
device offers high level support of layer-2 functions of the LAPD protocol.
Aside from ISDN applications, the ICC can be used as a general purpose communication
controller in all applications calling for LAPD, LAPB or other HDLC/SDLC based
protocols.
Semiconductor Group
6
ISDN Communication Controller
(ICC)
PEB 2070
PEF 2070
Preliminary Data
CMOSIC
1
Features
● Support of LAPD protocol
● Different types of operating modes
for increased flexibility
● FIFO buffer (2 x 64 bytes) for efficient
transfer of data packets
● Serial interfaces:
IOM®-1, SLD, SSI
IOM®-2
P-LCC-28-R
● General purpose HDLC communication interface
● Implementation of IOM-1/IOM-2 MONITOR
and C/I channel protocol to control layer 1
and peripheral devices
● D-channel access with contention
resolution mechanism
● µP access to B channel and
intercommunication channels
P-DIP-24
● B-channels switching
● Watchdog timer
● Test loops
● Advanced CMOS technology
● Low power consumption:
active
: 17 mW
: 8 mW
: 3 mW
(IOM-2)
(IOM-1)
standby
Type
Ordering Code
Package
PEB 2070-N
PEB 2070-P
PEF 2070-N
Q67100-H6213
Q67100-H6212
H67100-H6246
P-LCC-28-R (SMD)
P-DIP-24
P-LCC-28-R (SMD)
Semiconductor Group
7
01.94
Features
1.1 Pin Configuration
(top view)
P-LCC-28-R
P-DIP-24
AD4
AD5
1
24
23
22
21
20
19
18
17
16
15
14
AD3
AD2
AD1
AD0
RD
2
3
2
1 28 27
AD6
3
AD7 (D7)
4
5
6
7
8
9
26 AD1(D1)
25 AD0 (D0)
24 RD (DS)
23 WR (R/W)
A1
SDAR/A2
SDAX/SDS1
SCA/FSD/SDS2
RES
AD7
4
SDAR
5
PEB 2070
ICC
VDD
22
SDAX/SDS1
SCA/FSD/SDS2
RES
6
WR
VDD
21 CS
20 ALE
19 A0
18 INT
PEB 2070
ICC
FSC
10
7
A3
11
12
A4
8
CS
13 14 15 16 17
FSC
9
ALE
INT
V
ITP00697
SIP/EAW
DCL
10
11
12
IDP0
IDP1
VSS
13
ITP00696
Semiconductor Group
8
Features
1.1 Pin Definitions and Functions
Pin No.
P-DIP
Pin No.
P-LCC
Symbol
Input (I)
Output (O)
Function
21
22
23
24
1
2
3
4
25
26
27
28
1
2
3
4
AD0/D0
AD1/D1
AD2/D2
AD3/D3
AD4/D4
AD5/D5
AD6/D6
AD7/D7
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
MultiplexedBusMode: Address/Data
bus. Transfers addresses from the µP
system to the ICC and data between
the µP system and the ICC.
Non Multiplexed Bus Mode: Data
bus. Transfers data between the µP
system and the ICC.
17
21
CS
I
Chip Select. A “Low” on this line se-
lects the ICC for read/write operation.
–
23
R/W
I
Read/Write. When “High”, identifies a
valid µP access as a read operation.
When “Low”, identifies a valid µP
access as a write operation (Motorola
bus mode).
19
–
23
24
WR
DS
I
Write. This signal indicates a write
operation (Siemens/Intel bus mode).
I
Data Strobe. The rising edge marks
the end of a valid read or write
operation (Motorola bus mode).
Read. This signal indicates a read
operation (Siemens/Intel bus mode).
20
15
24
18
RD
I
INT
OD
Interrupt Request. The signal is
activated when the ICC request an
interrupt. It is an open drain output.
Address Latch Enable. A high on this
line indicates an address on the
external address bus (Multiplexed bus
typ only).
16
20
ALE
I
Semiconductor Group
9
Features
Pin Definitions and Functions (cont’d)
Pin No.
P-DIP
Pin No.
P-LCC
Symbol
Input (I)
Output (O)
Function
7
8
SCA
O
Serial Clock Port A, IOM-1 timing
mode. A 128-kHz data clock signal for
serial portA (SSI).
7
8
FSD
O
Frame Sync Delayed, IOM-1 timing
mode1. An 8-kHz synchronization
signal, delayed by 1/8 of a frame, for
IOM-1 is supplied. In this mode a
minimal round-trip delay for B1 and B2
channels is guaranteed.
7
8
SDS2
O
Serial Data Strobe 2, IOM-2 mode. A
programmable strobe signal, selecting
either one or two B or IC channels on
IOM-2 interface, is supplied via this
line.
After reset, SCA/FSD/SDS2 takes on
the function of SDS2 until a write
access to SPCR is made.
8
9
9
RES
FSC
I/O
Reset. A “High” on this input forces the
ICC into reset state. The minimum
pulse length is four clock periods.
If the terminal specific functions are
enabled, the ICC may also supply a
reset signal.
10
I
Frame Sync.
Input synchronization signal.
IOM-2 mode: Indicates the be-
ginning of IOM frame.
IOM-2 mode: Indicates the be-
ginning of IOM and,
if TSF = 0, frame
(timing mode 0).
Indicates the be-
ginning of SLD frame
(timing mode 1).
HDLC-mode: Strobe signal of
programmable pola-
rity.
Semiconductor Group
10
Features
Pin Definitions and Functions (cont’d)
Pin No.
P-DIP
Pin No.
P-LCC
Symbol
Input (I)
Output (O)
Function
11
14
DCL
I
Data Clock.
IOM modes: Clock of the frequen-
cy equal to twice the
data on the IOM in-
terface.
HDLC mode: Clock of frequency
equal to the data on
serial port B.
19
5
A0
A1
I
I
Address bit 0 (Non-multiplexed bus
type).
Address bit 1 (Non-multiplexed bus
type).
6
6
A2
I
I
Address bit 2 (Non-multiplexed bus
type)
Serial Data Port Receive.
6
SDAR
Serial data is received on this pin at
standard TTL or CMOS level. An
integrated pull-up circuit enables
connection of an open-drain/ open
collector driver without an external pull-
up resistor. SDAR is used only if IOM-1
mode is selected.
11
12
A3
A4
I
I
Address bit 3 (Non-multiplexed bus
type).
Address bit 4 (Non-multiplexed bus
type).
13
13
A5
I
Address bit 5 (Non-multiplexed bus
type).
10
10
SIP
I/O
SLD Interface Port, IOM-1 mode. This
line transmits and receives serial data
at standard TTL or CMOS levels.
External Awake (terminal specific
function). If a falling edge on this input
is detected, the ICC generates an
interrupt and, if enabled, a reset pulse..
13
EAW
I
Semiconductor Group
11
Features
Pin Definitions and Functions (cont’d)
Pin No.
P-DIP
Pin No.
P-LCC
Symbol
Input (I)
Output (O)
Function
6
7
SDAX
0
Serial Data Port A transmit, IOM-1
mode. Transmit data is shifted out via
this pin at standard TTL or CMOS
levels.
6
7
SDS1
0
Serial Data Strobe 1, IOM-2 mode. A
programmable strobe signal, selecting
either one or two B or IC channels on
IOM-2 interface, is supplied via this
line.
After reset, SDAX/SDS1 takes on the
function of SDS1 until a write access to
SPCR is made.
12
18
14
13
15
22
17
16
V
V
SS
DD
–
Ground (0 V)
–
Power supply (5 V ± 5%)
IOM Data Port 0
IOM Data Port 1
IDP0
IDP1
I/O
I/O
Semiconductor Group
12
Features
1.2 Logic Symbol
+ 5 V
VDD
0 V
VSS
RESET
RES
SDAX/SDS1
SDAR
SSI
(Serial Port A)
SLD
SIP/EAW
IDP0
IDP1
R
IOM
(Serial Port B)
DCL
FSC
Clock/Frame
Synchronization
SCA/FSD/SDS2
AD0 - 7
WR
RD
(D0 - 7) (A0 - 5)
CS (R/W) (DS) INT ALE
ITL00695
µP
Semiconductor Group
13
Features
1.3 Functional Block Diagram
SSI
B-Channel
Switching
Serial
Port A
R
IOM
R
Interface
IOM
SLD
D-Channel
Handling
SIP
(Serial Port B)
FIFO
µP Interface
ITB00698
µP
Semiconductor Group
14
Features
1.4 System Integration
1.4.1 ISDN Applications
The reference model for the ISDN basic access according to CCITT I series recommendations
consists of
– an exchange and trunk line termination in the central office (ET, LT)
– a remote network termination in the user area (NT)
– a two-wire loop (U interface) between NT and LT
– a four-wire link (S interface) which connects subscriber terminals and the NT in the user
area as depicted in figure 1.
ISDN User Area
TE
ISDN Central Office
S
U
NT
LT
ET
NT1
NT2
NT1
T
TE
ITS00699
Figure 1
ISDN Subscriber Basic Access Architecture
The NT equipment serves as a converter between the U interface at the exchange and the S
interface at the subscriber premises. The NT may consist of either an NT1 only or an NT1 to-
gether with an NT2 connected via the T interface which is physically identical to the S interface.
The NT1 is a direct transformation between layer 1 of S and layer 1 of U. NT2 may include
higher level functions like multiplexing and switching as in a PABX.
Semiconductor Group
15
Features
In terms of channels the ISDN access consists of:
● a number of 64 kbit/s bearer channels (n x B)
e.g. n = 2 for basic rate ISDN access
n = 30 or 23 for primary rate ISDN access;
● and a signaling channel (D), either 16 (basic rate) or 64 (primary rate) kbit/s
(figure 2).
Layer 3 and Up
Layer 2
Layer 1
Layer 2
B
B
B
D
B
D
ISDN-
Network
ISDN
User
Mainframe
Terminals
Telemetry
Q.930/1
Q.920/1
Q.910/1; I.430
I.431
ITS00700
Figure 2
ISDN Basic Access Channel Structure
Semiconductor Group
16
Features
The B channels are used for end-to-end circuit switched digital connections between
communicating stations.
The D channel is used to carry signaling and data via protocols defined by the CCITT. These
protocols cover the network services layers of the open system interconnection model (Layers
1-3). At layer 2, the data link layer, an HDLC type protocol is employed, the link access
procedure on the D channel LAPD (CCITT Rec. Q. 920/1).
The ISDN Communication Controller PEB 2070 can be used in all ISDN applications involving
establishment and maintenance of the data link connection in either the D channel or B
channel. It also provides the interface to layer-1 functions controlled via the IOM which links
the ICC to any transceiver or peripheral device. Depending on the interface mode, the ICC
supports three serial interfaces and offers switching functions and µP access to voice/ data
channels.
The applications comprise:
– Use as a signaling controller for the D channel
– Access to the D channel for data transmission
– Source/ sink for secured B-channel data
and the target equipment include:
– ISDN terminal
– ISDN PABX (NT2) and Central Office (ET) line card
– ISDN packet switches
– “Intelligent” NT1.
Terminal Applications
The concept of the ISDN basic access is based on two circuit-switched 64 kbit/s B channels
and a message oriented 64 kbit/s D channel for packetized data, signaling and telemetry
information.
Figure 3 shows an example of an integrated multifunctional ISDN terminal using the ICC.
The transceiver provides the layer-1 connection to the transmission line, either an S or U
interface, and is connected to the ICC and other, peripheral modules via the IOM-2 interface.
The D channel, containing signaling data and packet switched data, is processed by the ICC
LAPD controller and routed via a parallel µP interface to the terminal processor. The high level
support of the LAPD protocol which is implemented by the ICC allows the use of a low cost
processor in cost sensitive applications.
The IOM-2 interface is used to connect diverse voice/data application modules:
– sources/ sinks for the D channel
– sources/ sinks for the B1 and B2 channels.
Semiconductor Group
17
Features
IOM R -2
Speech
D, C/I
MON
D, C/I
B1
IC1
B2
IC2
SBCX PEB 2081
IBC PEB 2095
or
R
ICC
PEB 2070
ICC
PEB 2070
ARCOFI
Data
Encryption
HSCX
SAB 8252X
Processing
PSB 2160
IEC PEB 2090
s Packets
p Packets
µC
µC
µC
Terminal
Controller
Packet Data
Module
Data Modules
Speech Modules
ITD00701
Figure 3
Example of ISDN Voice/Data Terminal
Different D-channel services (for different SAPI’s) can be simply implemented by connecting
an additional ICC in parallel to the first one, for instance for transmitting p-packets in the D
channel.
Up to eight ICCs may thus be connected to the D and C/I (Command/Indication) channels via
the TIC bus. The ICCs handle contention autonomously.
Data transfer between the terminal controller and the different modules are done with the help
of the IOM-2 MONITOR channel protocol. Each voice/data module can be accessed by an
individual address. The same protocol enables the control of terminal modules that do not have
an associated microcontroller (such as the Audio Ringing Codec Filter ARCOFI® : PSB 2160)
and the programming of intercommunication inside the terminal. Two intercommunication
channels IC1 and IC2 allow a 2 x 64 kbit/s transfer rate between voice/data modules.
In the example above (figure 3), one ICC is used for data packets in the D channel. A voice
processor is connected to a programmable digital signal processing codec filter via IC1 and a
data encryption module to a data device via IC2. B1 is used for voice communication, B2 for
data communication.
The ICC ensures full upward compatibility with IOM-1 devices. It provides the additional strobe,
clock and data lines for connecting standard combos or data devices via IOM, or serial SLD
and SSI interfaces. The strobe signals and the switching of B channels is programmable.
Semiconductor Group
18
Features
Line Card Application
An example of the use of the ICC on an ISDN LT + ET line card (decentralized architecture)
is shown in figure 4.
The transceivers (ISDN Cancellation Circuit IEC: PEB 2090) are connected to an Extended
PCM Interface Controller (EPIC® PEB 2055) via an IOM interface.
This interface carries the control and data for up to eight subscribers using time division
multiplexing. The ICCs are connected in parallel on IOM, one ICC per subscriber.
The EPIC performs dynamic B- and D-channel assignment on the PCM highways. Since this
component supports four IOM interfaces, up to 32 subscribers may be accommodated.
1.4.2 Other Applications
If programmed in non-ISDN mode, the ICC serial port B operates as an HDLC communication
link without IOM frame structure. This allows the use of the ICC has a general purpose com-
munication controller. The valid HDLC data is marked by a strobe signal on serial port B. Ex-
amples of the use of the ICC are: X.25 packet controllers, terminal adaptors, and packet trans-
mission e.g. in primary rate/ DMI systems.
PEB 2070
System
ICC
Interface
R
IOM
PEB 2090
IEC-T
U Interface
U Interface
PCMHW0
PCMHW1
B + D
PEB 2055
EPICTM
D
PEB 2090
IEC-T
PEB 2070
ICC
D
SAB 82520
HSCC or
SAB 82525
HSCX
PCMHW0
PCMHW1
µP
ITS00702
Figure 4
ISDN Line Card Implementation
Semiconductor Group
19
Features
1.4.3 Microprocessor Environment
The ICC is especially suitable for cost-sensitive applications with single-chip microcontrollers
(e.g. SAB 8048 / 8031 / 8051). However, due to its programmable micro interface and non-
critical bus timing, if fits perfectly into almost any 8-bit microprocessor system environment.
The microcontroller interface can be selected to be either of the Motorola type (with control
signals CS, R/W, DS) of the Siemens/Intel non-multiplexed bus type (with control signals CS,
WR, RD) or of the Siemens/Intel multiplexed address/data bus type (CS, WR, RD, ALE).
SLD
SSI
+ 5 V
INT(INTX)
RD
INT
RD
RD
WR
ALE
WR
WR
ALE
SAB
80C51,
(80C188)
ALE
ICC
PEB 2070
R
IOM
(PSCX)
CS
A15
A8
AD7...AD0
AD7... AD0
AD0 - AD7
Latch
Common Bus A15 - A0, D7 - D0
ITS00703
Memory
Figure 5
Example of ICC Microcontroller Environment
Semiconductor Group
20
Functional Description
12ds Functional Description
2.1 General Functions and Device Architecture
DCL FSC
Timing Unit
B-Channel
SDAR
SSI
(Serial
SDAX/SDS1
Switching
R
Port A)
IDP0
IDP1
IOM
SCA/FSD/SDS2
(Serial
Port B)
SLD
SIP/EAW
HDLC
Receiver
HDLC
Transmitter
LAPD
Controller
Status/
Command
Registers
R-FIFO
2 x 32 byte
X-FIFO
2 x 32 byte
FIFO
Controller
RES
VSS
VDD
µP-Interface
ITS00704
AD0 - AD7
(D0 - D7)
(A0 - A5)
RD (DS)
WR (R/W)
ALE
Figure 6
Architecture of the ICC
Semiconductor Group
21
Functional Description
The functional block diagram in figure 6 shows the ICC to consist of:
– serial interface logic for the IOM and the SLD and SSI interfaces, with B-channel switching
capabilities
– logic necessary to handle the D-channel messages (layer 2)
The latter consists of an HDLC receiver and an HDLC transmitter together with 64-byte deep
FIFO’s for efficient transfer of the messages to/ from the user’s CPU.
In a special HDLC controller operating mode, the auto mode, the ICC processes protocol
handshakes (I and S frames) of the LAPD (Link Access Procedure on the D channel)
autonomously.
Control and MONITOR functions as well as data transfers between the user’s CPU and the D
and B channel are performed by the 8-bit parallel µP interface logic.
The IOM interface allows interaction between layer-1 and layer-2 functions. It implements D-
channel collision resolution for connecting other layer-2 devices to the IOM interface, and the
C/I and MONITOR channel protocols (IOM-1/IOM-2) to control peripheral devices.
This function is called TIC-Bus-Access-Procedure.
The timing unit is responsible for the system clock and frame synchronization.
2.2 Serial Interface Modes
The PEB 2070 can be used in different modes of operation:
● IOM-1 Mode
● IOM-2 Mode
● HDLC Controller Mode.
These modes are selected via bit IMS (Interface Mode Select) in ADF2 register and bits
DIM2-0 (Digital Interface Mode) in MODE register. See table 1.
Table 1
Interface Modes
IMS
DIM2
Mode
0
1
IOM-1 Mode
HDLC Mode
0
1
X
IOM-2 Mode
Semiconductor Group
22
Functional Description
2.2.1 IOM®-1 Mode (IMS = 0, DIM2 = 0)
Serial port B is used as the IOM-1 interface, which connects the ICC to layer-1 component.
The HDLC controller is always connected to the D channel of the IOM-1 interface.
Two additional serial interfaces are available in this mode, the Synchronous Serial Interface
SSI (Serial Port A) and the Subscriber Line Datalink (SLD) interface.
The SSI is used especially in ISDN terminal applications for the connection of B-channel
sources/sinks. It is available if timing mode 0 (Bit SPM = 0, SPCR register) is programmed.
The SLD is used:
– in ISDN terminal applications for the connection of SLD compatible B-channel devices
– in line card applications for the connection of a peripheral line board controller (e.g.
PEB 2050).
The connections of the serial interfaces in both terminal and exchange applications are shown
in figure 7.
The SSI interface is only available in timing mode 0 (SPM = 0). Timing mode 1 (SPM = 1) is
only applicable in exchange applications figure 7b and is used to minimize the B channel
round-trip delay time for the SLD interface. Refer to section 2.3.2.
Semiconductor Group
23
Functional Description
ISDN
Basic Access
S or Interface
R
R
IOM
e.g. ITAC
ICC
PSB 2110
SDAX
SDAR
SCA
SBC PEB 2080
SSI
IDP0
or
R
IBC PEB 2095
or
IEC PEB 2090
IOM
IDP1
SIP
SLD
R
ARCOFI
PSB 2160
FSC
DCL
(a) Timing Mode 0 (SPM = 0)
ISDN
Basic Access
S or Interface
System
Interface
R
IOM
ICC
SBC PEB 2080
IDP0
IDP1
Peripheral
SIP
or
R
Board Controller
SLD
IBC PEB 2095
or
IOM
PEB 2050/52/55
IEC PEB 2090
System Clock
Sync Pulse
FSD
FSC
DCL
( b)Timing Mode 1 (SPM = 1)
ITS00705
Figure 7
ICC Interfaces in IOM®-1 Mode
Semiconductor Group
24
Functional Description
The characteristics of the IOM interface are determined by bits DIM1, 0 as shown in table 2.
Table 2
IOM®-1 Interface Mode Characteristics
DIM1
DIM0 Characteristics
0
0
1
MONITOR channel upstream is used for TIC bus access.
0
MONITOR channel upstream is used for TIC bus access. Bit
3 of MONITOR channel downstream is evaluated to control
D-channel transmission.
1
1
0
1
MONITOR channel is used for TIC bus access and for data
transfer.
MONITOR channel is used for TIC bus access, for data
transfer and for D-channel access control.
2.2.2 IOM®-2 Mode (IMS = 1)
Serial port B is operated as an IOM-2 interface for the connection of layer-1 devices, and as a
general purpose backplane bus in terminal equipment. The auxiliary serial SSI and SLD
interfaces are not available in this case.
The functions carried out by the IOM are determined by bits SPCR:SPM (terminal mode/non-
terminal mode) and DIM2-0, as shown in table 3.
Table 3
IOM®-2 Interface Mode Characteristics
DIM2
DIM1
DIM0 Characteristics
HDLC in D channel:
Last octet of IOM channel 2 is used for TIC bus access.
0
0
0
0
0
1
Applicable in terminal mode (SPM = 0).
Last octet of IOM channel 2 is used for TIC bus access, bit
5 of last octet is evaluated to control D-channel
transmission. Applicable in terminal mode (SPM = 0).
No TIC bus access and no S bus D-channel access control.
Applicable in terminal and non-terminal mode.
0
0
1
1
0
1
Bit 5 of last octet is evaluated to control D-channel
transmission. Applicable in terminal mode (SPM = 0).
HDLC in B or IC channel:
No transmission/reception in D channel.
HDLC channel selected by ADF2:D1C2-0.
1
1
0
Semiconductor Group
25
Functional Description
Note: In IOM-2 terminal mode (SPM = 0, 12-byte IOM-2 frame), all DIM2 – 0 combinations
are meaningful. When IOM-2 non-terminal mode is programmed (SPM = 1), the only
meaningful combination is “10”.
2.2.3 HDLC Controller Mode (IMS = 0, DIM2 = 1)
In this case serial port B has no fixed frame structure, but is used as a serial HDLC port. The
valid HDLC data is market by a strobe signal input via pin FSC. The data rate is determined by
the clock input DLC (maximum 4096 Mbit/s). The characteristic of the serial port B are
determined by bits DIM1, 0 as shown in table 4.
Table 4
HDLC Mode Characteristics
DIM1
DIM0 Characteristics
0
0
1
0
1
reserved
0
1
1
FSC strobe active low
FSC strobe active high
FSC strobe ignored
2.3 Interfaces
The ICC serves three different user-oriented interface types:
– parallel processor interface to higher layer functions
– IOM interface: between layer 1 and 2, and as a universal backplane for terminals
– SSI and SLD interfaces for B-channel sources and destinations (in IOM-1 mode only).
Semiconductor Group
26
Functional Description
2.3.1 µP Interface
The ICC is programmed via an 8-bit parallel microcontroller interface. Easy and fast
microprocessor access is provided by 8-bit address decoding on chip. The interface consists
of 13 (18) lines and is directly compatible with multiplexed and non-multiplexed microcontroller
interfaces (Siemens/Intel or Motorola type buses). The microprocessor interface signals are
summarized in table 5.
Table 5
Interface of the ICC
Pin No.
P-DIP
Pin No.
P-LCC
Symbol
Input (I)
Output (O)
Function
21
22
23
24
1
2
3
4
25
26
27
28
1
2
3
4
AD0/D0
AD1/D1
AD2/D2
AD3/D3
AD4/D4
AD5/D5
AD6/D6
AD7/D7
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
Multiplexed Bus Mode: Address/
Data bus. Transfers addresses from
the µP system to the ICC and data
between the µP system and the ICC.
Non Multiplexed Bus Mode: Data
bus. Transfers data between the µP
system and the ICC.
CS
17
–
21
23
I
Chip Select. A 0 “low” on this line
selects the ICC for read/write
operation.
R/W
I
Read/Write. At 1 “high”, identifies a
valid µP access as a read operation.
At 0, identifies a valid µP access as a
write operation (Motorola bus mode).
Write. This signal indicates a write
operation (Siemens/Intel bus mode).
19
–
23
WR
DS
I
24
I
Data Strobe. The rising edge marks
the end of a valid read or write
operation (Motorola bus mode).
Read. This signal indicates a read
operation (Siemens/Intel bus mode).
20
24
RD
I
Semiconductor Group
27
Functional Description
Interface of the ICC (cont’d)
Pin No.
P-DIP
Pin No.
P-LCC
Symbol
Input (I)
Output (O)
Function
15
18
INT
OD
I
Interrupt Request. The signal is
activated when the ICC requests an
interrupt. It is an open drain output.
16
20
ALE
Address Latch Enable. A high on this
line indicates an address on the
external address bus (Multiplexed bus
typ only).
19
5
A0
A1
A2
A3
A4
A5
I
I
I
I
I
I
Address bit 0 (Non-multiplexed bus
type).
Address bit 1 (Non-multiplexed bus
type).
6
Address bit 2 (Non-multiplexed bus
type).
11
12
13
Address bit 3 (Non-multiplexed bus
type).
Address bit 4 (Non-multiplexed bus
type).
Address bit 5 (Non-multiplexed bus
type).
2.3.2 ISDN Oriented Modular (IOM®) Interface
IOM®-1
This interface consists of one data line per direction (IOM Data Ports 0 and 1: IDP0,1). Three
additional signals define the data clock (DCL) and the frame synchronization (FSC/FSD) at this
interface. The data clock has a frequency of 512 kHz (twice the data rate) and the frame sync
clock has a repetition rate of 8 kHz.
Via this interface four octets are transmitted per 125 µs frame (figure 8):
– The first two octets constitute the two 64 kbit/s B channels.
– The third octet is the MONITOR channel. It is used for the exchange of data using the IOM-
1 MONITOR channel protocol which involves the E bit as a validation bit. In addition, it
carries a bit which enables/inhibits the transmission of HDLC frames (IDP0) and it serves to
arbitrate the access to the last octet. (IDP1).
– The fourth octet is called the Telecom IC (TIC) bus because of the offered busing capability.
It is constituted of the 16 kbit/s D channel (2 bits), a four-bit Command/Indication channel
and the T and E bits. The C/I channel serves to control and MONITOR layer-1 functions (e.g.
activation/deactivation of a transmission line...). The T bit is a transparent 8-kbit/s channel
which can be accessed from the ICC, and the E bit is used in MONITOR byte transfer.
Semiconductor Group
28
Functional Description
125
µs
Bits
8
8
8
2
4
1
T
1
Frame
R
IOM
D
C/1
E
B1
B2
MONITOR
Layer 2
Layer 1
8 kbit/s
8 kbit/s
32 kbit/s
16 kbit/s
64 kbit/s
64 kbit/s
64 kbit/s
TIC-Bus
D
Channel
MONITOR
Channel
B
Channels
ITD00706
Figure 8
IOM®-1 Frame Structure
TIC Bus and Arbitration via MONITOR Channel
The arbitration mechanism implemented in the MONITOR channel allows the access of more
than one (up to eight) ICC to the last octet of IOM (TIC). This capability is useful for the modular
implementation of different ISDN services (different Service Access Points) e.g. in ISDN voice/
data terminals. The IDP1 pins are connected together in a wired-or configuration, as shown in
figure 9.
Semiconductor Group
29
Functional Description
IDP1
IDP0
FSC
DCL
ICC
ISDN Basic
Access S or
U Interface
Layer 1
SBS,IBC
or IEC
or
1
IDP1
IDP00
ICC
Layer 1+ 2
FSC
DCL
ISAC R -S or ISAC R -P
ITS00707
Figure 9
IOM® Bus (TIC Bus) Configuration
The arbitration mechanism is described in the following.
An access request to the TIC bus may either be generated by software (µP access to the C/I
channel) or by the ICC itself (transmission of an HDLC frame). A software access request to
the bus is effected by setting the BAC bit (CIXR/CIX0 register) to “1”.
Semiconductor Group
30
Functional Description
In the case of an access request, the ICC checks the bus accessed-bit (bit 3 of IDP1
MONITOR octet) for the status “bus free”, which is indicated by a logical “1”. If the bus is free,
the ICC transmits its individual TIC bus address programmed in STCR register. The TIC bus
is occupied by the device which is able to send its address error-free. If more than one device
attempt to seize the bus simultaneously, the one with the lowest address value wins.
MONITOR Channel Structure on IDP1
7
6
5
4
3
2
1
0
TIC Bus Address TBA2-0
-Bus accessed = “1” (no TIC bus
access) if
-BAC = 0
(CIXR/CIX0
register) and
- no HDLC
transmission is in
progress
When the TIC bus is seized by the ICC, the bus is identified to other devices as occupied via
the IDP1 MONITOR channel bus accessed bit state “0” until the access request is withdrawn.
After a successful bus access, the ICC is automatically set into a lower priority class, that is, a
new bus access cannot be performed until the status “bus free” is indicated in two successive
frames.
If none of the devices connected to the IOM interface request access to the D and C/I
channels, the TIC bus address 7 will be present. The device with this address will therefore
have access, by default, to the D and C/I channels.
Note: Bit BAC (CIXR/CIX0 register) should be reset by the µP when access to the C/I channel
is no more requested, to grant other devices access to these channels.
Semiconductor Group
31
Functional Description
MONITOR Channel
The MONITOR channel protocol for data transfer is described in section 2.4.5.
When the ICC is used in connection with an S interface layer-1 transceiver, an indication must
be given to the ICC whether the D channel is available for transmission (TE applications with
short passive or extended bus configuration).
This indication is assumed to be given in bit 3 “Stop/Go” (S/G) of the MONITOR input channel
on IDP0. When a HDLC frame is to be transmitted in the D channel, the ICC automatically
starts, proceeds with, or stops frame transmission according to the S/G bit value:
S/G = 1 : stop
S/G = 0 : go
MONITOR Channel Structure IDP0
7
6
5
4
3
2
1
0
1
1
1
1
S/G
1
1
1
IOM®-1 Timing
In IOM-1 mode, the ICC may be operated either in timing mode 0 or timing mode 1. The
selection is via bit SPM in SPCR register.
Timing mode 0 (SPM = 0) is used in terminal applications. Timing mode 1 (SPM = 1) is only
meaningful in exchange applications when the SLD is used. Programming timing mode 1
minimizes the B-channel round-trip delay time on the SLD interface.
In timing mode 0 the IOM frame begin is marked by a rising edge on the FSC input. It
simultaneously marks the beginning of the SLD frame.
In timing mode 1 the IOM frame begins is marked by a rising edge on FSD output. The FSD
output is delayed by the ICC by 1/8 th of a frame with respect to FSC (figure 10).
Semiconductor Group
32
Functional Description
( )
Ι
DCL
(512 kHz)
( )
Ι
FSC
(8 kHz)
125 µs
SLD OUT
B2 FC
SLD IN
FC
B1
SIG
B1
B2
SIG
SIP
IOM R Frame
IDP0/1
B1
B2
MONITOR
TIC
SSI Frame
SDAR/SDAX
B2
B1
( a) Timing Mode 0
( )
Ι
DCL
(512 kHz)
( )
Ι
FSC
(8 kHz)
125 µs
( )
FSD 0
SIP
1/8 Frame Period
SLD OUT
SLD IN
B1
B2
FC
SIG
B1
B2
FC
SIG
IOM R Frame
IDP0/1
B1
B2
MONITOR
TIC
( b) Timing Mode 1
ITD00708
Figure 10
Interface Timing in IOM®-1 Mode
Note: The up-arrows show the position, where register contents are transferred to the sender,
the down-arrows show the position, where the receiver transfers data to the registers.
Semiconductor Group
33
Functional Description
IOM®-2
The IOM-2 is a generalization and enhancement of the IOM-1. While the basic frame structure
is very similar, IOM-2 offers further capacity for the transfer of maintenance information. In
terminal applications, the IOM-2 constitutes a powerful backplane bus offering
intercommunication and sophisticated control capabilities for peripheral modules.
The channel structure of the IOM-2 is depicted below.
Channel Structure of the IOM®-2
B1
B2
MONITOR
D
C/I
MR
MX
● The first two octets constitute the two 64 kbit/s B channels.
● The third octet is the MONITOR channel. It is used for the exchange of data between the
ICC and the other attached device(s) using the IOM-2 MONITOR channel protocol.
● The fourth octet (control channel) contains
– two bits for the 16 kbit/s D channel
– a four-bit Command/Indication channel
– two bits MR and MX for supporting the MONITOR channel protocol.
In the case of an IOM-2 interface the frame structure depends on whether TE- or non-TE mode
is selected, via bit SPM in SPCR register.
Non-TE Timing Mode (SPM = 1)
In this case the frame is a multiplex of eight IOM-2 channels (figure 11), each channel has the
same structure.
Thus the data rate per subscriber connection (corresponding to one channel) is
256 kbit/s, whereas the bit rate is 2048 kbit/s. The IOM-2 interface signals are:
IDP0,1
DCL
:
:
:
2048 kbit/s
4096 kHz input
8 kHz input
FSC
Semiconductor Group
34
Functional Description
s
125 µ
FCS
DCL
DU
R
CH0
CH0
CH1
CH1
CH2
CH2
CH3
CH3
CH4
CH5
CH5
CH6
CH6
CH7
CH7
CH0
CH0
IOM
IOM
R
CH4
DD
MM
RX
B1
B2
MONITOR
D
C/I
ITD00709
Figure 11
Multiplexed Frame Structure of the IOM®-2 Interface in Non-TE Timing Mode
The ICC is assigned to one of the eight channels (0 to 7) via register programming.
This mode is used in ISDN exchange/line card applications.
TE Timing Mode (SPM = 0)
The frame is composed of three channels (figure 11):
● Channel 0 contains 144 kbit/s (for 2B + D) plus MONITOR and command/indication
channels for layer-1 devices.
● Channel 1 contains two 64-kbit/s intercommunication channels plus MONITOR and
command/indication channels for other IOM-2 devices.
● Channel 2 is used for enabling/inhibiting the transmission of HDLC frames. This bit is
typically generated by an S-bus transceiver (stop/go: bit 5, or 3rd MSB of the last octet on
IDP0). On IDP1, bits 2 to 5 of the last octet are used for TIC bus access arbitration.
As in the IOM-1 case (figure 9), up to eight ICCs can access the TIC bus (D and C/I channels).
The bus arbitration mechanism is identical to that described previously, except that it involves
bits 2 to 5 in channel 2.
Semiconductor Group
35
Functional Description
FSC
IOM R CH0
IOM R CH0
IOM R CH0
IDP0
B1
B1
B2
MON0
D
D
C/I0
IC1
MX
IC1
IC2
MON1 C/I1
MR
MR
MX
MX
S/G
IDP1
B2
MON0
C/I0
IC2
MON1 C/I1
MR
C/I2
TIC-Bus
SDS1/2
ITD00710
Figure 12
Definition of the IOM®-2 Channels in Terminal Timing Mode
The IOM-2 signals are:
IDP0,1
DCL
:
:
:
768 kbit/s
1536 kHz input
8 kHz input.
FSC
In addition, to support standard combos/data devices the following signals are generated as
outputs:
SDS1/2 :
8 kHz programmable data strobe signals for selecting one or both B/IC
channel(s).
2.3.3 SSI (Serial Port A)
The SSI (Serial Synchronous Interface) is available in IOM-1 interface mode. Timing mode 0
(SPM = 0) has to be programmed.
The serial port SSI has a data rate of 128 kbit/s. It offers a full duplex link for B channels in
ISDN voice/data terminals. Examples: serial synchronous transceiver devices (USART’s,
HSCX SAB 82525, ITAC PSB 2110, …), and CODEC filters.
The port consists of one data line in each direction (SDAX and SDAR) and the 128-kHz clock
output (SCA). The beginning of B2 is marked by a rising edge on FSC, see figure12.
The µC system has access to B-channel data via the ICC registers BCR1/2 and BCX1/2.
The µC access must be synchronized to the serial transmission by means of the Synchronous
Transfer Interrupt (STCR see chapter 4).
Semiconductor Group
36
Functional Description
2.3.4 SLD
The SLD is available in IOM-1 interface mode.
( )
Ι
FSC
(8 kHz)
( )
SDAR
Ι
B2
B2
B1
B1
SDAX (0)
SCA (0)
128 kHz
a) SSI
SLD OUT
SLD IN
SIP (Ι/Ο)
B1
B2
FC
SIG
B1
B2
FC
SIG
DCL ( Ι )
512 kHz
b) SLD
ITD00711
Figure 13
SSI (a) and SLD (b) Interface Lines
The standard SLD interface is a three-wire interface with a 512-kHz clock input (DCL), an 8-
kHz frame direction signal input (FSC), and a serial ping-pong data lead (SIP) with an effective
full duplex data rate of 256 kbit/s.
The frame is composed of four octets per direction. Octets 1 and 2 contain the two B channels,
octet 3 is a feature control byte, and octet 4 is a signaling byte (figure 13).
The SLD interface can be used in:
– Terminal applications as a full duplex time-multiplexed (ping-pong) connection to B-
channel sources/destinations. CODEC filters, such as the SICOFI® (PEB 2060) or the
ARCOFI® (PSB 2160) as well as other SLD compatible voice/data modules may be
connected directly to the ICC as depicted in figure 13a. Terminal specific functions have to
be deselected (TSF = 0), so that pin SIP/EAW takes on its proper function as SLD data line.
Moreover, in TE applications timing mode 0 has to be programmed.
Semiconductor Group
37
Functional Description
– Digital exchange applications as a full duplex time-multiplexed connection to convey the
B channels between the layer-1 devices and a Peripheral Board Controller (e.g. PBC PEB
2050 or PIC PEB 2052), which performs time-slot assignment on the PCM highways,
forming a system interface to a switching network (figure 13b).
Timing mode 1 (SPM = 1) can be programmed in order to minimize the B-channel round-
trip delay.
The µC system has access to B-channel data, the feature control byte and the signaling byte
via the ICC registers:
– C1R, C2R
B1/B2
FC
– CFCR and SFCX
– SSCR and SSCX
SIG
The µP access to C1R, C2R, SFCR, SFCX, SSCR and SSCX must be synchronized to the
serial transmission by means of the Synchronous Transfer Interrupt (STCR) and the BVS-bit
(STAR).
2.4 Individual Functions
2.4.1 Layer-2 Functions for HDLC
The HDLC controller in the ICC is responsible for the data link layer using HDLC/SDLC based
protocols.
The ICC can be made to support that data link layer to a degree that best suits system
requirements. When programmed in auto mode, it handles elements of procedure of an
acknowledged, balanced class of HDLC protocol autonomously (window size equal to “1”).
Multiple links may be handled simultaneously due to the address recognition capabilities, as
explained in section 2.4.1.1.
The ICC supports point-to-point protocols such as LAPB (Link Access Procedure Balanced)
used in X.25 networking.
For ISDN, one particularly important protocol is the Link Access Procedure for the D
channel (LAPD).
Semiconductor Group
38
Functional Description
LAPD, layer 2 of the ISDN D-channel protocol (CCITT I.441) includes functions for:
– Provision of one or more data link connections on a D channel (multiple LAP).
Discrimination between the data link connections is performed by means of a data link
connection identifier (DLCI = SAPI + TEI)
– HDLC-framing
– Application of a balanced class of procedure in point-multipoint configuration.
The simplified block diagram in figure 6 shows the functional blocks of the ICC which support
the LAPD protocol.
The HDLC transceiver in the ICC performs the framing functions used in HDLC/SDLC based
communication: flag generation/recognition, bit stuffing, CRC check and address recognition.
The FIFO structure with two 64-byte pools for transmit and receive directions and an intelligent
FIFO controller permit flexible transfer of protocol data units to and from the µC system.
2.4.1.1Message Transfer Modes
The HDLC controller can be programmed to operate in various modes, which are different in
the treatment of the HDLC frame in receive direction. Thus, the receive data flow and the
address recognition features can be programmed in a flexible way, to satisfy different system
requirements.
In the auto mode the ICC handles elements of procedure of the LAPD (S and I frames)
according to CCITT I.441 fully autonomously.
For the address recognition the ICC contains four programmable registers for individual SAPI
and TEI values SAP1-2 and TEI1-2, plus two fixed values for “group” SAPI and TEI, SAPG and
TEIG.
There are 5 different operating modes which can be set via the MODE register:
Auto mode (MDS2, MDS1 = 00)
Characteristics:
– Full address recognition (1 or 2 bytes).
– Normal (mod 8) or extended (mod 128) control field format
– Automatic processing of numbered frames of an HDLC procedure
(see 2.4.1.2).
If a 2-byte address field is selected, the high address byte is compared with the fixed value FEH
or FCH (group address) as well as with two individually programmable values in SAP1 and
SAP2 registers. According to the ISDN LAPD protocol, bit 1 of the high byte address will be
interpreted as COMMAND/RESPONSE bit (C/R) dependent on the setting of the CRI bit in
SAP1, and will be excluded from the address comparison.
Similarly, the low address byte is compared with the fixed value FFH (group TEI) and two
compare values programmed in special registers (TEI1, TEI2). A valid address will be
recognized in case the high and low byte of the address field match one of the compare values.
The ICC can be called (addressed) with the following address combinations:
Semiconductor Group
39
Functional Description
– SAP1/TEI1
– SAP1/FFH
– SAP2/TEI2
– SAP2/FFH
– FEH(FCH)/TEI1
– FEH(FCH)/TEI2
– FEH(FCH)/FFH
Only the logical connection identified through the address combination SAP1, TEI1 will be
processed in the auto mode, all others are handled as in the non-auto mode. The logical
connection handled in the auto mode must have a window size 1 between transmitted and
acknowledged frames. HDLC frames with address fields that do not match with any of the
address combinations, are ignored by the ICC.
In case of a 1-byte address, TEI1 and TEI2 will be used as compare registers. According to
the X.25 LAPB protocol, the value in TEI1 will be interpreted as COMMAND and the value in
TEI2 as RESPONSE.
The control field is stored in RHCR register and the I field in RFIFO. Additional information is
available in RSTA.
Non-Auto Mode (MDS2, MDS1 = 01)
Characteristics: Full address recognition (1 or 2 bytes)
Arbitrary window sizes
All frames with valid addresses (address recognition identical to auto mode) are accepted and
the bytes following the address are transferred to the µP via RHCR and RFIFO. Additional
information is available in RSTA.
Transparent Mode 1 (MDS2, MDS1, MDS0 = 101).
Characteristics: TEI recognition
A comparison is performed only on the second byte after the opening flag, with TEI1, TEI2 and
group TEI (FFH). In case of a match, the first address byte is stored in SAPR, the (first byte of
the) control field RHCR, and the rest of the frame in the RFIFO. Additional information is
available in RSTA.
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40
Functional Description
Transparent Mode 2 (MDS2, MDS1, MDS0 = 110).
Characteristics: non address recognition.
Every received frame is stored in RFIFO (first byte after opening flag to CRC field). Additional
information can be read from RSTA.
Transparent Mode 3 (MDS2, MDS1, MDS0 = 111)
Characteristics: SAPI recognition
A comparison is performed on the first byte after the opening flag with SAP1, SAP2 and group
SAPI (FE/FCH). In the case of a match, all the following bytes are stored in RFIFO. Additional
information can be read from RSTA.
2.4.1.2Protocol Operations (auto mode)
In addition to address recognition all S and I frames are processed in hardware in the auto
mode. The following functions are performed:
– update of transmit and receive counter
– evaluation of transmit and receive counter
– processing of S commands
– flow control with RR/RNR
– response generation
– recognition of protocol errors
– transmission of S commands, if an acknowledgment is not received
– continuous status query of remote station after RNR has been received
– programmable timer/repeater functions.
The processing of frames in auto mode is described in detail in section 2.4.8.
Semiconductor Group
41
Functional Description
2.4.1.3Reception of Frames
A 2x32-byte FIFO buffer (receive pools) is provided in the receive direction.
The control of the data transfer between the CPU and the ICC is handled via interrupts.
There are two different interrupt indications concerned with the reception of data:
– RPF (Receive Pool Full) interrupt, indicating that a 32-byte block of data can be read from
the RFIFO and the received message is not yet complete.
– RME (Receive Message End) interrupt, indicating that the reception of one message is
completed, i.e. either
● one message ≤ 32 bytes, or
● the last part of a message ≥ 32 bytes
is stored in the RFIFO.
Depending on the message transfer mode the address and control fields of received frames
are processed and stored in the receive FIFO or in special registers as depicted in figure 14.
The organization of the RFIFO is such that, in the case of short ( ≤ 32 bytes), successive
messages, up to two messages with all additional information can be stored. The contents of
the RFIFO would be, for example, as shown in figure 15.
RFIFO
Interrupts in
Wait Line
0
Receive
Message 1
_
<
(
32 bytes)
31
0
RME
Receive
Message 2
_
<
(
32 bytes)
RME
31
ITS01502
Figure 14
Contents of RFIFO (short message)
Semiconductor Group
42
Functional Description
Address
High
Address
Low
Flag
Control
Information
CRC
Flag
Auto-Mode
(U and I frames)
SAP1,SAP2
FE,FC
TEI1,TEI2
FF
RHCR
RFIFO
RFIFO
RFIFO
RSTA
RSTA
RSTA
RSTA
RSTA
(Note 1)
(Note 2)
(Note 3)
Non-Auto
Mode
SAP1,SAP2
FE,FC
TEI1,TEI2
FF
RHCR
(Note 1)
(Note 2)
(Note 4)
Transparent
Mode 1
TEI1,TEI2
FF
SAPR
SAPR
RFIFO
RFIFO
Transparent
Mode 2
Transparent
Mode 3
SAP1,SAP2
FE,FC
ITD02872
Description of Symbols:
Checked automatically by ICC
Compared with register or fixed value
Stored into register or RFIFO
Figure 15
Receive Data Flow
Note 1
Note 2
Only if a 2-byte address field is defined (MDS0 = 1 in MODE register).
Comparison with Group TEI (FFH) is only made if a 2-byte address field is
defined (MDS0 = 1 in MODE register).
Note 3
Note 4
In the case of an extended, modulo 128 control field format (MCS = 1
in SAP2 register) the control field is stored in RHCR in compressed
form (I frames).
In the case of extended control field, only the first byte is stored in RHCR, the
second in RFIFO.
Semiconductor Group
43
Functional Description
When 32 bytes of a message longer than that are stored in RFIFO, the CPU is prompted to
read out the data by an RPF interrupt. The CPU must handle this interrupt before more than
32 additional bytes are received, which would cause a “data overflow” (figure 16). This
corresponds to a maximum CPU reaction time of 16 ms (data rate 16 kbit/s).
After a remaining block of less than or equal to 16 bytes has been stored, it is possible to store
the first 16 bytes of a new message (see figure 16b).
The internal memory is now full. The arrival of additional bytes will result in “data overflow” and
a third new message in “frame overflow”.
The generated interrupts are inserted together with all additional information into a wait line to
be individually passed to the CPU.
After an RPF or RME interrupt has been processed, i.e. the received data has been read from
the RFIFO, this must be explicitly acknowledged by the CPU issuing a RMC (Receive
Message Complete) command.
The ICC can then release the associated FIFO pool for new data. If there is an additional
interrupt in the wait line it will be generated after the RMC acknowledgment.
Semiconductor Group
44
Functional Description
RFIFO
the Queue
Interrupts in
RFIFO
Interrupts in
the Queue
0
0
Long
Long
Message
Message 1
_
<
46 bytes)
(
31
0
31
0
RPF
RPF
15
16
RME
Message 2
_
<
(
32 bytes)
31
31
RPF
RME
ITS01501
Figure 16
Contents of RIFIFO (long message)
Information about the received frame is available for the µP when the RME interrupt is
generated, as shown in table 6.
Semiconductor Group
45
Functional Description
Table 6
Receive Information at RME Interrupt
Information
Register
Bit
Mode
First byte after SAPR
flag (SAPI of
LAPD address
field)
–
Transparent mode 1
Control field
RHCR
RHCR
–
–
Auto mode, I (modulo 8) and U frames
Auto mode, I frames (modulo 128)
Compressed
control field
2nd byte after
flag
3rd byte after
flag
RHCR
RHCR
–
Non-auto mode, 1-byte address field
–
Non-auto mode, 2-byte address field
Transparent mode 1
Type of frame STAR
(Command/
Response)
C/R
Auto mode, 2-byte address field
Non-auto mode, 2-byte address field
Transparent mode 3
Recognition of STAR
SAPI
SA1-0
Auto mode, 2-byte address field
Non-auto mode, 2-byte address field
Transparent mode 3
Recognition of STAR
TEI
TA
All expect Transparent mode 2,3
Result of CRC STAR
check (correct/
incorrect)
CRC
ALL
Data available STAR
in RFIFO (yes/
no)
RDA
RAB
RDO
ALL
ALL
ALL
Abort condition STAR
detected
(yes/no)
Data overflow
during recep-
tion of a frame
(yes/no)
STAR
Number of
bytes recei-
ved in RFIFO
RBCL
RBC4-0
ALL
ALL
Message
length
RBCL
RBCH
RBC11-
50V
Semiconductor Group
46
Functional Description
2.4.1.4Transmission of Frames
A 2x32 byte FIFO buffer (transmit pools) is provided in the transmit direction.
If the transmit pool is ready (which is true after an XPR interrupt or if the XFW bit in STAR is
set), the CPU can write a data block of up to 32 bytes to the transmit FIFO. After this, data
transmission can be initiated by command.
Two different frame types can be transmitted:
– Transparent frames (command: XTF), or
– I frames (command: XIF)
as shown in figure 17.
* Transmit
Transparent
Frame
XFIFO
* Transmit
I Frame
(auto-mode only!)
XAD1
XAD2
XFIFO
Transmitted
HDLC Frame
Address
High
Address
Low
Flag
Control
INFORMATION
CRC
Flag
If 2 byte
address
field
Appended if CPU
has issued
transmit message
end (XME)
selected
commend.
ITD02862
Description of Symbols:
Generated automatically by ICC
Written initially by CPU (into register)
Loaded (repeatedly) by CPU upon ICC request (XPR interrupt)
Figure 17
Transmit Data Flow
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47
Functional Description
For transparent frames, the whole frame including address and control field must be written to
the XFIFO.
The transmission of I frames is possible only if the ICC is operating in the auto mode. The
address and control field is autonomously generated by the ICC and appended to the frame,
only the data in the information field must be written to the XFIFO.
If a 2-byte address field has been selected, the ICC takes the contents of the XAD 1 register
to build the high byte of the address field, and the contents of the XAD 2 register to build the
low byte of the address field.
Additionally the C/R bit (bit 1 of the high byte address, as defined by LAPD protocol) is set to
“1” or “0” dependent on whether the frame is a command or a response.
In the case of a 1-byte address, the ICC takes either the XAD 1 or XAD 2 register to
differentiate between command or response frame (as defined by X.25 LAP B).
The control field is also generated by the ICC including the receive and send sequence number
and the poll/final (P/F) bit. For this purpose, the ICC internally manages send and receive
sequence number counters.
In the auto mode, S frames are sent autonomously by the ICC. The transmission of U frames,
however, must be done by the CPU. U frames must be sent as transparent frames (XTF), i.e.
address and control field must be defined by the CPU.
Once the data transmission has been initiated by command (XTF or XIF), the data transfer
between CPU and ICC is controlled by interrupts.
The ICC repeatedly requests another data packet or block by means of an XPR interrupt, every
time no more than 32 bytes are stored in the XFIFO.
The processor can then write further data to the XFIFO and enable the continuation of frame
transmission by issuing an XIF/XTF command.
If the data block which has been written last to the XFIFO completes the current frame, this
must be indicated additionally by setting the XME (Transmit Message End) command bit. The
ICC then terminates the frame properly by appending the CRC and closing flag.
If the CPU fails to respond to an XPR interrupt within the given reaction time, a data underrun
condition occurs (XFIFO holds no further valid data). In this case, the ICC automatically aborts
the current frame by sending seven consecutive “ones” (ABORT sequence).
The CPU is informed about this via an XDU (Transmit Data Underrun) interrupt.
It is also possible to abort a message by software by issuing an XRES (Transmitter RESet)
command, which causes an XPR interrupt.
After an end of message indication from the CPU (XME command), the termination of the
transmission operation is indicated differently, depending on the selected message transfer
mode and the transmitted frame type.
If the ICC is operating in the auto mode, the window size (= number of outstanding
unacknowledged frames) is limited to 1; therefore an acknowledgment is expected for every I
frame sent with an XIF command. The acknowledgment may be provided either by a received
S or I frame with corresponding receive sequence number (see figure 14).
Semiconductor Group
48
Functional Description
If no acknowledgment is received within a certain time (programmable), the ICC requests an
acknowledgment by sending an S frame with the poll bit set (P = 1) (RR or RNR). If no
response is received again, this process is repeated in total CNT times (retry count,
programmable via TIMR register).
The termination of the transmission operation may be indicated either with:
– XPR interrupt, if a positive acknowledgment has been received,
– XMR interrupt, if a negative acknowledgment has been received, i.e. the transmitted
message must be repeated (XMR = Transmit Message Repeat),
– TIN interrupt, if no acknowledgment has been received at all after CNT times the expiration
of the time period t1 (TIN = Timer INterrupt, XPR interrupt is issued additionally).
Note: Prerequisite for sending I frames in the auto mode (XIF) is that the internal operational
mode of the timer has been selected in the MODE register (TMD bit = 1).
The transparent transmission of frames (XTF command) is possible in all message transfer
modes. The successful termination of a transparent transmission is indicated by the XPR
interrupt.
In the case where an IOM interface mode is programmed (see section 2.2), a transmission
may be aborted from the outside by setting the stop/go bit to 1, provided DIM1 - 0 are
programmed appropriately, see tables 2 and 3. An example of this is the occurrence of an S
bus D-channel collision. - If this happens before the first FIFO pool has been completely
transmitted and released, the ICC will retransmit the frame automatically as soon as
transmission is enabled again. Thus no µP interaction is required.
On the other hand, if a transmission is inhibited by the stop/go bit after the first pool has already
been released (and XPR generated), the ICC aborts the frame and requests the processor to
repeat the frame with an XMR interrupt.
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49
Functional Description
2.4.2 B-Channel Switching (IOM®-1)
The ICC contains two serial interfaces, SLD and SSI, which can serve as interfaces to B-
channel sources/destinations. Both channels B1 and B2 can be switched independently of one
another to the IOM interface (figure 18).
The following possibilities are provided:
– Switching from/to SSI
– Switching from/to SLD
– IOM looping
– SLD looping
The microcontroller can select the B-channel switching in the SPCR register. In figure 19 all
possible selections of the B-channel routes and access to B-channel data via the
microprocessor interface are illustrated. This access from the microcontroller is possible by
writing or reading the C1R/C2R register or reading the B1CR/B2CR register (cf. Synchronous
Transfer, paragraph 2.4.3).
SSI
SSI
R
B-Channel
Sources/Destinations
IOM
Interface
SLD
SLD
Registers: C1R/C2R
B1CR/B2CR
SPCR
µP-Interface
ITS02863
Figure 18
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50
Functional Description
FF
H
SSI
SSI
R
R
IOM
IOM
)
*
FF
SLD
SLD
H
µP
µP
SSI Switching
SLD Switching
= µP Access
= B-Channel Route
FF
FF
H
SSI
SSI
H
R
R
FF
IOM
IOM
H
)
*
FF
SLD
SLD
H
µP
µP
IOM R Loop
SLD Loop
) B1 = FF
*
H
ITS00863
B2 = Undefines Value
Figure 19
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51
Functional Description
2.4.3 Access to B / IC Channels
IOM®-1 mode (IMS = 0)
The B1 and/or B2 channel is accessed by reading the B1CR/B2CR or by reading and writing
the C1R/C2R registers. The µP access can be synchronized to the serial interface by means
of a Synchronous Transfer programmed in the STCR register.
The read/write access possibilities are shown in table 7.
Table 7
C_R
B_CR
C_C1
C_C0
Read
SLD
SLD
SSI
Write
SLD
–
Read Application(s)
0
0
1
1
0
1
0
1
IOM
IOM
IOM
–
B_not switched, SLD looping
B_switched to/from SLD
B_switched to/from SSI
IOM looping
–
IOM
IOM
The Synchronous Transfer Interrupt (SIN, ISTA register) can be programmed to occur at either
the beginning of a 125 µs frame or at its center, depending on the channel(s) to be accessed
and the current configuration, see figure 20a.
Semiconductor Group
52
Functional Description
(a) C_C1, C_C0 = 00
SLD Loop
R
SIP
SLD
IOM
IDP1
B_CR
C_R
µP
FSC
BVS
IDP1
B1
B2
SLD
B1
B2
B1
B2
OUT
IN
µP Access
SIN (STO)
ITS02864
Figure 20a
Semiconductor Group
53
Functional Description
(b) C_C1, C_C0 = 01
R
SLD - IOM Connection
IDP0
C_R
R
SIP
SLD
IOM
IDP1
B_CR
µP
FSC
BVS
IDP0
SIP
B1
B2
B1
B2
B1
B2
µP Access
IDP1
B1
B2
ITS02969
SIN (STO)
Figure 20b
Semiconductor Group
54
Functional Description
(c) C_C1, C_C0 = 10
R
SSI - IOM Connection
SDAR
SDAX
IDP0
C_R
R
SSI
IOM
IDP1
B_CR
µP
FSC
SDAR
IDP0
B2
B1
B1
B2
IDP1
B1
B2
SDAX
B1
B2
BCHAN 3
µP Access
B1/2 IOM
B2 SSI
SIN (STO)
µP Access
R
B1
SSI
SIN (STI)
ITS02865
Figure 20c
Semiconductor Group
55
Functional Description
IOM®-2 mode (IMS = 1)
The B1, B2 and/or IC1, IC2 channels are accessed by reading the B1CR/B2CR or by reading
and writing the C1R/C2R registers. The µP access can be synchronized to the IOM interface
by means of a Synchronous Transfer programmed in the STCR register.
The read/write access possibilities are shown in table 8.
Table 8
C_C1
C_C0 C_R
Read
C_R
B_CR Output Application(s)
to
Write
Read
IOM2
0
0
1
1
0
IC_
–
B_
–
B_monitoring, IC_monitoring
1
IC_
–
IC_
B_
B_
B_
B_
–
IC_ B_monitoring, IC_looping from/to
IOM
0
B_
B_
B_access from/to IOM;
transmission of a constant
value in B_channel to IOM.
B_
1
B_looping from IOM;
transmission of a variable
pattern in B_channel to IOM.
The general sequence of operations to access the B/IC channels is:
(set configuration, register SPCR)
Program Synchronous Interrupt (ST0)
Read Register (B_CR, C_R)
SIN
(Write register)
Acknowledge SIN (SC0)
Note: The data transfer itself works independent of the Synchronous Transfer Interrupt. In
case of a SOV e.g. transfer is still possible.
Semiconductor Group
56
Functional Description
2.4.4 C/I Channel Handling
The Command/Indication channel carries real-time status information between the ICC and
another device connected to the IOM.
1) One C/I channel conveys the commands and indications between a layer-1
device and a layer-2 device. This channel is available in all timing modes (IOM-1
or IOM-2). It can be accessed from the microcontroller e.g. to control the layer-1
activation/deactivation procedures. Access is arbitrated via the TIC bus
access protocol:
– in IOM-1 mode, this arbitration is done in the MONITOR channel
– in IOM-2 TE timing mode (SPM = 0), this arbitration is done in C/I channel 2
(see figure 11).
This C/I channel is access via register CIRR/CIR0 (in receive direction layer 1-
to-layer 2) and register CIXR/CIX0 (in transmit direction, layer 2-to-layer 1).
The code is four bits long.
In the receive direction, the code from layer 1 is continuously monitored, with an
interrupt being generated anytime a change occurs. A new code must be found
in two consecutive IOM frames to be considered valid and to trigger a C/I
code change interrupt status (double last look criterion).
In the transmit direction, the code written in CIXR/CIX0 is continuously transmitted
in the channel.
2) A second C/I channel (called C/I1) can be used to convey real time status
information between the ICC and various non-layer 1 peripheral devices.
The channel consists of six bits in each direction. It is available only in the
IOM-2 terminal timing mode (see figure 11).
The C/I1 channel is accessed via registers CIR1 and CIX1. A change in
the received C/I1 code is indicated by an interrupt status without double
last look criterion.
2.4.5 MONITOR Channel Handling
IOM®-1
The MONITOR channel protocol can be used to exchange one byte of information at a time
between the ICC and another device (e.g. layer-1 transceiver).
The procedure is as follows:
MONITOR Transmit Channel (MOX) register is loaded with the value to be sent in the outgoing
MONITOR channel. (Bytes of the form FxH are not allowed for this purpose because of the TIC
bus collision resolution procedure).
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57
Functional Description
The receiving device interprets the incoming MONITOR value as a control/information byte,
FxH excluded. If no response is expected, the procedure is complete. If the receiving device
shall react by transmitting information to the ICC, it should set the E bit to 0 and send the
response in the MONITOR channel of the following frame. The ICC
– latches the value in the MONITOR channel of the frame immediately following a frame with
“E = 0” into MOR register.
– generates a MONITOR Status interrupt MOS (EXIR register) to indicate that the MOR
register has been loaded. See figure 21.
MON
IDP1
IDP0
X
X
Y
E
0
MON
E
0
MON
=
F
H
MOR Load, MOS Int.
MOR Load, MOS Int.
ITD00868
Figure 21
IOM®-2
In this case, the MONITOR channel protocol is a handshake protocol used for high speed
information exchange between the ICC and other devices, in MONITOR channel 0 or 1 (see
figure 11). In the non-TE mode, only one MONITOR channel is available (“MONITOR channel
0”).
The MONITOR channel protocol is necessary (see figure 22):
● For programming and controlling devices attached to the IOM. Examples of such devices
are: layer-1 transceivers (using MONITOR channel 0), and peripheral V/D modules that do
not have a parallel microcontroller interface (MONITOR channel 1), such as the Audio
Ringing Codec Filter PSB 2160.
● For data exchange between two microcontroller systems attached to two different devices
on one IOM-2 backplane. Use of the MONITOR channel avoids the necessity of a dedicated
serial communication path between the two systems. This greatly simplifies the system
design of terminal equipment (figure 22).
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58
Functional Description
Data Communication (MONITOR 1)
Control
Control
(MONITOR 1)
(MONITOR 0)
V/D Module e.g.
Layer 1 e.g.
PEB
IEC PEB 2090
V/D Module
ARCOFI R PSB 2160
ITAC R PSB 2110
ICC
IBC
2095
ITS02866
µC
µC
Figure 22
Examples of MONITOR Channel Applications
The MONITOR channel operates on an asynchronous basis. While data transfers on the bus
take place synchronized to frame sync, the flow of data is controlled by a handshake procedure
using the MONITOR Channel Receive (MR0 or 1) and MONITOR Channel Transmit (MX0 or
1) bits. For example: data is placed onto the MONITOR channel and the MX bit is activated.
This data will be transmitted repeatedly once per 8-kHz frame until the transfer is
acknowledged via the MR bit.
The microprocessor may either enforce a “1” (idle) in MR, MX by setting the control bit MRC1,0
or MXC1,0 to “0” (MONITOR Control Register MOCR), or enable the control of these bits
internally by the ICC according to the MONITOR channel protocol. Thus, before a data
exchange can begin, the control bit MRC(1,0), or MXC(1,0) should be set to “1” by the
microprocessor.
The MONITOR channel protocol is illustrated in figure 23. Since the protocol is identical in
MONITOR channel 0 and MONITOR channel 1 (available in TE mode only), the index 0 or 1
has been left out in the illustration.
The relevant status bits are:
MONITOR Channel Data Received MDR (MDR0, MDR1)
MONITOR Channel End of Reception MER (MER0, MER1)
for the reception of MONITOR data, and
MONITOR Channel Data Acknowledged MDA (MDA0, MDA1)
MONITOR Channel Data Abort MAB (MAB0, MAB1)
for the transmission of MONITOR data (Register: MOSR).
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59
Functional Description
In addition, the status bit:
MONITOR Channel Active MAC (MAC0, MAC1)
indicates whether a transmission is in progress (Register: STAR).
MX
0 1
MR
0 1
µ
µ
P :
P :
Transmitter
Receiver
MRE=1
WR Data
MXC =1, MIE =1
MAC = 1 Status
MDR Int.
MDR Int.
~
~
RD Data
MRC =1, MIE =1
MDA Int.
~
~
~
~
WR Data
~
~
~
~
RD Data
RD Data
MDA Int.
~
~
~
~
WR Data
MDR Int.
MER Int.
~
~
~
~
MDA Int.
~
~
~
~
MXC = 0
~
~
MRC = 0, MIE = 0
MAC = 0 Status
ITD03481
Figure 23
Before starting a transmission, the microprocessor should verify that the transmitter is inactive,
i.e. that a possible previous transmission has been terminated. This is indicated by an “0” in
the MONITOR Channel Active MAC status bit.
After having written the MONITOR Data Transmit (MOX) register, the microprocessor sets the
MONITOR Transmit Control bit MXC to 1. This enables the MX bit to go active (0), indicating
the presence of valid MONITOR data (contents of MOX) in the corresponding frame.
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60
Functional Description
As a result, the receiving device stores the MONITOR byte in its MONITOR Receive MOR
register and generates a MDR interrupt status.
Alerted by the MDR interrupt, the microprocessor reads the MONITOR Receive (MOR)
register. When it is ready to accept data (e.g. based on the value in MOR, which in a point-to-
multipoint application might be the address of the destination device), it sets the MR control bit
MRC to “1” to enable the receiver to store succeeding MONITOR channel bytes and
acknowledge them according to the MONITOR channel protocol. In addition, it enables other
MONITOR channel interrupts by setting MONITOR Interrupt Enable to “1”.
As a result, the first MONITOR byte is acknowledged by the receiving device setting the MR
bit to “0”. This causes a MONITOR Data Acknowledge MDA interrupt status at the transmitter.
A new MONITOR data byte can now be written by the microprocessor in MOX. The MX bit is
still in the active (0) state. The transmitter indicates a new byte in the MONITOR channel by
returning the MX bit active after sending it once in the inactive state. As a result, the receiver
stores the MONITOR byte in MOR and generates anew a MDR interrupt status. When the
microprocessor has read the MOR register, the receiver acknowledges the data by returning
the MR bit active after sending it once in the inactive state. This in turn causes the transmitter
to generate a MDA interrupt status.
This “MDA interrupt - write data - MDR interrupt - read data - MDA interrupt” handshake is
repeated as long as the transmitter has data to send. Note that the MONITOR channel protocol
imposes no maximum reaction times to the microprocessor.
When the last byte has been acknowledged by the receiver (MDA interrupt status), the
microprocessor sets the MONITOR Transmit Control bit MXC to 0. This enforces an inactive
(“1”) state in the MX bit. Two frames of MX inactive signifies the end of a message. Thus, a
MONITOR Channel End of Reception MER interrupt status is generated by the receiver when
the MX is received in the inactive state in two consecutive frames. As a result, the
microprocessor sets the MR control bit MRC to 0, which in turn enforces an inactive state in
the MR bit. This marks the end of the transmission, making the MONITOR Channel Active
MAC bit return to “0”.
During a transmission process, it is possible for the receiver to ask a transmission to be
aborted by sending an inactive MR bit value in two consecutive frames. This is effected by the
microprocessor writing the MR control bit MRC to 0. An aborted transmission is indicated by a
MONITOR Channel Data Abort MAB interrupt status at the transmitter.
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61
Functional Description
2.4.6 Terminal Specific Functions
In addition to the standard functions supporting the ISDN basic access, the ICC contains
optional functions, useful in various terminal configurations.
The terminal specific function are enabled by setting bit TSF (STCR register) to “1”. This has
two effects:
●
●
The SIP/EAW line is defined as External Awake input (and not as SLD line);
Second, the interrupts SAW and WOV (EXIR register) are enabled:
– SAW (Subscriber Awake) generated by a falling edge on the EAW line
– WOV (Watchdog Timer Overflow) generated by the watchdog timer. This occurs when
the processor fails to write two consecutive bit patterns in ADF1:
WTC1
WTC2
ADF1
Watchdog Timer Control 1,0.
The WTC1 and WTC2 bits have to be successively written in the following manner within 128
ms:
WTC1
WTC2
1.
2.
1
0
0
1
As a result the watchdog timer is reset and restarted. Otherwise a WOV is generated.
Deactivating the terminal specific functions is only possible with a hardware reset.
Having enable the terminal specific functions via TSF = 1, the user can make the ICC generate
a reset signal by programming the Reset Source Select RSS bit (CIX0 register), as follows:
0
A reset signal is generated as a result of
– a falling edge on the EAW line (subscriber awake)
– a C/I code change (exchange awake).
A falling edge on the EAW line also forces the IDP1 line of the
IOM interface to zero.
Note: This should normally induce the attached layer-1 device to
leave the power down state and supply clocking to ICC
via DCL and FSC.
A corresponding interrupt status (CIC or SAW) is also generated.
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62
Functional Description
1
A reset signal is generated as a result of the expiration of the
watchdog timer (indicated by the WOV interrupt status).
Note: That the watchdog timer is not running when the ICC is in
the power-down state (IOM not clocked).
Note: Bit RSS has a significance only if terminal specific functions are activated (TSF = 1).
The RSS bit should be set to “1” by the user when the ICC is in power-up to prevent an edge
on the EAW line or a change in the C/I code from generating a reset pulse.
Switching RSS from 0 to 1 or from 1 to 0 resets the watchdog timer.
The reset pulse generated by the ICC (output via RES pin) has a pulse width of 5 ms and is
an active high signal.
2.4.7 Test Functions
The ICC provides the following test and diagnostic functions:
● digital loop via TLP (Test Loop, SPCR register) command bit: IDP1 is internally connected
with IDP0, external input on IDP0 is ignored: this is used in system tests, to test layer-2
functionality independent of layer 1;
● special loops programmed via C2C1-0 and C1C1-0 bits (register SPCR, cf. 2.4.3).
Semiconductor Group
63
Functional Description
2.4.8 Documentation of the Auto Mode
The Auto Mode of the ICC and ISAC-S is only applicable for the states 7 and 8 of the LAPD
protocol. All other states (1 to 6) have to be performed in Non-Auto Mode (NAM). Therefore
this documentation gives an overview of how the device reacts in the states 7 and 8, which
reactions require software programming and which are done by the hardware itself, when
interrupts and status register contents are set or change. The necessary software actions are
also detailed in terms of command or mode register access.
The description is based on the SDL-Diagrams of the ETSI TS 46-20 dated 1989.
The diagrams are only annotated by documentary signs or texts (mostly register descriptions)
and can therefore easily be interpreted by anyone familiar with the SDL description of LAPD.
All deviations that occur are specially marked and the impossible actions, path etc. are crossed
out.
To get acquainted with this documentation, first read through the legend-description and the
additional general considerations, then start with the diagrams, referring to the legend and the
register description in the Technical Manual if necessary.
We hope you will profit from this documentation and use our software-saving auto mode.
Legend of the Auto Mode Documentation
a.
Symbols within a path
There are 3 symbols within a path
a.1
In the auto mode the device processes all subse-
quent state transitions branchings etc. up to the
next symbol.
a.2
a.3
In the auto mode the device does not process the
state transitions, branchings, etc. Within the path
appropriate directions are given with which the
software can accomplish the required action.
A path cannot be implemented and no software
or hardware action can change this. These path
are either optional or only applicable for
window-size > 1.
Semiconductor Group
64
Functional Description
b.
Symbols at a path
There is 1 symbol at a path
b.1
c
marks the beginning of a path, for which a.3
applies
Symbols at an internal or external message box.
There are 2 symbols at a message box.
c.1
This symbol means, that the action described in
the box is not possible. Either the action specified
is not done at all (box crossed out) or an additional
action is taken (written into the box).
box
Note: The impossibility to perform the optional
T203 timer-procedure is not explicitly
mentioned; the corresponding actions
are only crossed out.
box
c.2
This symbol means, that within a software-path, by
taking the prescribed register actions the contents
of the box will be done automatically.
d.
Text within boxes
Text within boxes can be grouped in one of two classes.
d.1
The text denotes an interrupt which is always
Text
box
associated with the event (but can also be
associated with other events). (See ISTA and
EXIR register description in the Technical
Manual for an interrupt description)
box
or
Text
d.2
The text describes a register access
either a register read access to discriminate this
state from others or to reach a branching condi-
tion.
box
Text
or a register write access to give a command.
The text is placed in the box that describes the functions for which
the register access is needed.
Semiconductor Group
65
Functional Description
e.
Text at the side of boxes
e.1
The text describes an interrupt associated with the
contents of the box. The interrupt is always asso-
ciated with the box contents, if the interrupt name
is not followed by a “/”, it is associated only
Text
Box
under appropriate conditions if a “/” is behind it.
e.1
The text describes a possible or mandatory chan-
ge of a bit in a status-register associated with the
contents of the box.
Box
Text
(The attached texts can also be placed on the left side.)
Text above and below boxes
f.
f.1
Text describes a mandatory action to performed
on the contents of the box.
Text
box
f.2
Text describes a mandatory action to be taken as
a result of the contents of the box.
Action here means register access.
Box
Text
g.
Shaded boxes
Box
The box describes an impossible state or action
for the device.
Semiconductor Group
66
Functional Description
Additional General Considerations when Using the Auto Mode
a)
Switching from Auto Mode to Non-Auto Mode.
As mentioned in the introduction the Auto Mode is only applicable in the states
7 and 8 of the LAPD. Therefore whenever these states have to be left (which is
indicated by a “Mode:NAM” text) there are several actions to be taken that could
not all be detailed in the SDL-diagrams:
a.1)
a.2)
write Non Auto Mode and TMD = 0 into the mode register.
write the timer register with an arbitrary value to stop it. The timer T200 as
specified in the LAPD-Protocol is implemented in the hardware only in the
states 7 and 8; in all other states this or any other timer-procedure
has to be done by the software with the possible use of the timer in
external timer mode
a.3)
read the WFA bit of the STAR2 register and store it in a software variable.
The information in this bit may be necessary for later decisions. When
switching from Auto Mode to Non-Auto Mode XPR interrupts may be lost.
a.4)
a.5)
a.6)
In the Non-Auto Mode the software has to decode I, U and S-frames
because I and S frames are only handled autonomously in the Auto Mode.
The RSC and PCE interrupts, the contents of the STAR2 register and the
RRNR bit in the STAR register are only meaningful within the Auto Mode.
leave some time before RHR or XRES is written to reset the counters, as a
currently sent frame may not be finished yet.
b)
What has to be written to the XFIFO?
In the legend description when the software has to write contents of a frame to the
XFIFO only “XFIFO” is shown in the corresponding box. We shall given here a
general rule of what has to be written to the XFIFO:
a)
For sending an I frame with CMDR:XIF, only the information field content,
i.e. no SAPI, TEI, control field should be written to the XFIFO
b)
For sending an U frame or any other frame with CMDR:XTF, the SAPI,
TEI and the control field has to be written to the XFIFO.
c)
The interrupts XPR and XMR.
The occurrence of an XPR interrupt in Auto Mode after an XIF command
indicates that the I frame sent was acknowledged and the next I frame can
be sent, if STAR2:TREC indicates state 7 and STAR:RRNR indicates Peer
Rec not busy. If Peer Rec is busy after an XPR, the software should wait
for the next RSC interrupt before sending the next I-frame. If the XPR hap-
pens to be in the Timer Recovery state, the software has to poll the
STAR2 register until the state Multiple Frame Established is reached or a
TIN interrupt is issued which requires Auto Mode to be left (One of these
two conditions will occur before the time T200xN200). In Non-Auto
Mode or after an XTF command the XPR just indicates, that the frame
was sent successfully.
Semiconductor Group
67
Functional Description
The occurrence of an XMR interrupt in Auto Mode after an XIF command indicates
that the I frame sent was either rejected by the Peer Entity or that a collision occu-
red on the S interface. In both cases the I frame has to be retransmitted (after an
eventual waiting for the RSC interrupt if the Peer Rec was busy; after an XMR the
device will always be in the state 7). In Non-Auto Mode or after an XTF command
the XMR indicates that a collision occurred on the S interface and the frame has
to be retransmitted.
d)
e)
The resetting of the RC variable:
The RC variable is reset in the ICC and ISAC-S when leaving the state Timer
Recovery. The SLD diagrams indicate a reset in the state Multiple Frame
Established when T200 expires. There is no difference to the outside world between
these implementations however our implementation is clearer.
The timer T203 procedure:
We do not fully support the optional timer T203 procedure, but we can still find out
whether or not S frames are sent on the link in the Auto Mode. By polling the
STAR2:SDET bit and (re)starting a software timer whenever a one is read we can
build a quasi T203 procedure which handles approximately the same task. When
T203 expires one is supposed to go into the Timer Recovery State with RC = 0.
This is possible for the ICC and ISAC-S by just writing the STI bit in the CMDR
register (Auto Mode and Internal Timer Mode assumed).
f)
The congestion procedure as defined in the 1 TR 6 of the “Deutsche Bundespost".
In the 1 TR 6a variable N2x4 is defined for the maximum number of Peer Busy
requests. The 1 TR is in this respect not compatible with the Q921 of CCITT or the
ETSI 46 – 20 but it is, nevertheless, sensible to avoid getting into a hangup
situation. With the ICC and ISAC-S this procedure can be implemented:
After receiving an RSC interrupt with RRNR set one starts a software – timer. The
timer is reset and stopped if one either receives another RSC interrupt with a reset
RRNR, if one receives a TIN interrupt or if other conditions occur that result in a
reestablishment of the link. The timer expires after N2x4xT200 and in this case the 1
TR 6 recommends a reestablishment of the link.
g)
Dealing with error conditions: The SLD diagrams do not give a very detailed
description of how to deal with errors. Therefore we prepared a special Application
Note:
“How to deal with an error condition of the LAPD-Protocol with your ICC
or ISAC-S”
Semiconductor Group
68
Functional Description
7
MULTIPLE
FRAME
ESTABLISHED
DL
DL
RELEASE
REQUEST
DL-DATA
REQUEST
I FRAME
QUEUED UP
ESTABLISH
REQUEST
PEER
RECEIVER
BUSY
YES
DISCARD
I QUEUE
DISCARD
I QUEUE
PUT IN
I QUEUE
STAR:RRNR
NO
I FRAME
QUEUED UP
ESTABLISH
DATA LINK
RC = 0
P = 1
YES
(V)S = V(A) + K
STAR2:WFA
NO
SET
LAYER 3
INITIATED
TX DISC
7
GET NEXT
I QUEUE
ENTRY
I FRAME
QUEUED UP
MULTIPLE
FRAME
ESTABLISHED
XFIFO
CMDR XTF
XFIFO
MODE NAM
STOP T203
RESTART T200
P = 0
5
AWAITING
ESTABLISHM.
TXI
COMMAND
MODE NAM
6
CMDR:XIF
AWAITING
RELEASE
V(S) = V(S) + 1
CLEAR
ACKNOWLEDGE
PENDING
YES
T200
RUNNING
NO
STOP T203
START T200
7
MULTIPLE
FRAME
ESTABLISHED
Note: The regeneration of this signal does not affect
the sequence integrity of the I queue.
ITD02365
Figure 24a
Semiconductor Group
69
Functional Description
7
MULTIPLE
FRAME
ESTABLISHED
TIMER
T200
EXPIRY
TIMER
T203
EXPIRY
MDL
REMOVE
REQUEST
PERSISTENT
DEACTIVATION
CMDR STI
RC = 0
DISCARD
I AND UI
QUEUES
DISCARD
I AND UI
QUEUES
TRANSMIT
ENQUIRY
DL RELEASE
INDICATION
DL RELEASE
INDICATION
RC = 0
YES
PEER
BUSY
NO
GET LAST
TRANSMITTED
I FRAME
8
TRANSMIT
ENQUIRY
STOP T200
STOP T203
STOP T200
STOP T203
TIMER
RECOVERY
STAR2:
TREC
V(S) = V(S) - 1
P = 1
1
TEI
4
TEI
UNASSIGNED
ASSIGNED
ITD02366
TX I
COMMAND
V(S) = V(S) + 1
CLEAR
ACKNOWLEDGE
PENDING
START T200
RC = RC + 1
8
TIMER
RECOVERY
STAR2:
TREC
Figure 24b
Semiconductor Group
70
Functional Description
7
MULTIPLE
FRAME
ESTABLISHED
RME
RME
RME
SABME
RCHR:
DISC
UA
RCHR:
RCHR:
MDL-ERROR
INDICATION
(C,D)
DISCARD
I QUEUE
F=P
STORE
STAR2:
WFA
TX UA
7
MULTIPLE
FRAME
ESTABLISHED
F = P
XFIFO
CMDR XTF
CLEAR
TX UA
EXCEPTION
CONDITIONS
XFIFO
CMDR XTF
MDL-ERROR
INDICATION
(F)
DL-RELEASE
INDICATION
STOP T200
STOP T203
V(S) = V(A)
YES
STAR2:WFA = 0
MODE NAM
NO
4
TEI
ASSIGNED
DISCARD
I QUEUE
DL
ESTABLISH
INDICATION
STOP T200
STOP T203
CMDR:RHR;XRES
V(S) = 0
V(A) = 0
V(R) = 0
7
MULTIPLE
FRAME
ESTABLISHED
ITD02367
Figure 24c
Semiconductor Group
71
Functional Description
7
MULTIPLE
FRAME
ESTABLISHED
RME
SET OWN
RECEIVER
BUSY
CLEAR OWN
RECEIVER
BUSY
DM
RHCR:
CLEAR
RECEIVER
BUSY
CLEAR
NO
F = 1
YES
YES
RECEIVER
RHCR
BUSY
NO
NO
YES
SET OWN
RECEIVER
BUSY
CLEAR OWN
RECEIVER
BUSY
MDL-ERROR
INDICATION
(E)
MDL-ERROR
INDICATION
(B)
CMDR:RNR = 1
STAR:XRNR
CMDR:RNR = 0
STAR:XRNR
7
ESTABLISH
DATA LINK
MULTIPLE
FRAME
F = 0
F = 0
ESTABLISHED
CLEAR
LAYER 3
INITIATED
TX RNR
RESPONSE
TX RR
RESPONSE
MODE NAM
5
CLEAR
ACKNOWLEDGE
PENDING
CLEAR
ACKNOWLEDGE
PENDING
AWAITING
ESTABLISHM.
7
MULTIPLE
FRAME
ESTABLISHED
Note: These signals are generated outside of this SDL representation,
and may be generated by the connection management entity.
ITD02368
Figure 24d
Semiconductor Group
72
Functional Description
7
MULTIPLE
FRAME
ESTABLISHED
RR
REJ
RSC /
RSC /
CLEAR PEER
RECEIVER
BUSY
CLEAR PEER
RECEIVER
BUSY
STAR:RRNR
STAR:RRNR
NO
NO
COMMAND
YES
COMMAND
YES
YES
YES
F = 1
F = 1
NO
NO
NO
NO
P = 1
P = 1
MDL-ERROR-
INDICATION
(A)
YES
YES
MDL-ERROR-
INDICATION
(A)
ENQUIRY
RESPONSE
ENQUIRY
RESPONSE
STAR2:SDET
STAR2:SDET
1
2
Figure 24f
Figure 24f
ITD03482
Figure 24e
Semiconductor Group
73
Functional Description
1
2
NO
NO
NO
_
_
_
_
<
<
<
<
V(A) N(R) V(S)
V(A) N(R) V(S)
YES
YES
PCE
XPR /
N(R) ERROR
RECOVERY
V(A) = N(R)
N(R) = V(S)
STAR2:WFA
YES
MODE NAM
XPR /
5
STOP T200
YES
V(A) = N(R)
AWAITING
ESTABLISHM.
N(R) = V(A)
NO
START T203
STAR2:WFA
XMR /
INVOKE
RETRANS-
MISSION
STOP T200
START T203
V(A) = N(R)
7
MULTIPLE
FRAME
RESTART T200
ESTABLISHED
7
MULTIPLE
FRAME
ESTABLISHED
ITD02370
Figure 24f
Semiconductor Group
74
Functional Description
7
MULTIPLE
FRAME
ESTABLISHED
RME
RNR
FRMR
RHCR:
RSC /
SET PEER
RECEIVER
BUSY
MDL-ERROR
INDICATION
(K)
STAR:RRNR
NO
COMMAND
YES
ESTABLISH
DATA LINK
YES
F = 1
CLEAR
LAYER 3
INITIATED
NO
NO
P = 1
YES
MODE NAM
MDL-ERROR-
INDICATION
(A)
5
AWAITING
ESTABLISHM.
ENQUIRY
RESPONSE
STAR2:SDET
NO
_
_
<
<
V(A) N(R) V(S)
YES
XPR /
PCE
N(R)
ERROR
RECOVERY
V(A) = N(R)
STAR2:WFA
MODE NAM
STOP T203
5
RESTART T200
RC = 0
AWAITING
ESTABLISHM.
7
MULTIPLE
FRAME
ESTABLISHED
ITD02371
Figure 24g
Semiconductor Group
75
Functional Description
7
MULTIPLE
FRAME
ESTABLISHED
I
COMMAND
OWN
RECEIVER
BUSY
YES
NO
NO
DISCARD
INFORMATION
N(S) = V(R)
YES
NO
DISCARD
INFORMATION
P = 1
V(R) = V(R) + 1
YES
REJECT
EXCEPTION
NO
CLEAR REJECT
EXCEPTION
NOTE 2
F = 1
YES
RME
DL-DATA
INDICATION
NO
SET
REJECT
P = 1
TX RNR
RFIFO, RHCR
EXCEPTION
STAR2:SDET
YES
YES
YES
CLEAR
ACKNOWLEDGE
PENDING
P = 1
NO
F = P
ACKNOWLEDGE
PENDING
TX REJ
F = P
STAR2:SDET
NO
CLEAR
ACKNOWLEDGE
PENDING
ACKNOWLEDGE
PENDING
TX RR
STAR2:SDET
NOTE 1
SET
CLEAR
ACKNOWLEDGE
PENDING
ACKNOWLEDGE
PENDING
ITD03483
3
Figure 24i
Note 1: Processing of acknowledge pending is described figure 24i
Note 2: This SDL representation does not include the optional procedure in Appendix I.
Figure 24h
Semiconductor Group
76
Functional Description
3
Figure 24h
NO
NO
V(A) N(R) V(S)
YES
PCE
N(R)
ERROR
RECOVERY
PEER
RECEIVER
BUSY
YES
MODE NAM
XPR /
5
NO
V(A) = N(R)
N(R) = V(S)
AWAITING
ESTABLISHM.
STAR2:WFA
YES
XPR /
YES
V(A) = N(R)
N(R) = V(A)
STAR2:WFA
NO
STOP T200
V(A) = N(R)
RESTART T203
RESTART T200
7
MULTIPLE
FRAME
ESTABLISHED
ITD03484
Figure 24i
Semiconductor Group
77
Functional Description
7
MULTIPLE
FRAME
ESTABLISHED
ACKNOWLEDGE
PENDING
NO
ACKNOWLEDGE
PENDING
YES
CLEAR
ACKNOWLEDGE
PENDING
F = 0
TX RR
STAR2:SDET
7
MULTIPLE
FRAME
ESTABLISHED
ITD02374
Figure 24j
Semiconductor Group
78
Functional Description
8
TIMER
RECOVERY
DL
DL
DL-DATA
REQUEST
I FRAME
QUEUED UP
ESTABLISH
REQUEST
ESTABLISH
REQUEST
DISCARD
I QUEUE
DISCARD
I QUEUE
PUT IN
I QUEUE
I FRAME
QUEUED UP
ESTABLISH
DATA LINK
RC = 0
P = 1
TX DISC
8
SET
TIMER
RECOVERY
LAYER 3
INITIATED
XFIFO
CMDR XTF
MODE NAM
5
AWAITING
ESTABLISHM.
RESTART T200
MODE NAM
6
AWAITING
RELEASE
ITD02375
Figure 25a
Semiconductor Group
79
Functional Description
8
TIMER
RECOVERY
MDL
REMOVE
REQUEST
TIMER
T200
EXPIRY
PERSISTENT
DEACTIVATION
YES
DISCARD
I AND UI
QUEUES
DISCARD
I AND UI
QUEUES
RC = N200
NO
V(S) = V(A)
NO
TIN
MDL-ERROR
INDICATION(I)
YES
DL-RELEASE
INDICATION
DL-RELEASE
INDICATION
ESTABLISH
DATA LINK
STOP T200
TIMR
STOP T200
TIMR
YES
PEER
BUSY
NO
MODE NAM
MODE NAM
CLEAR
LAYER 3
INITIATED
GET LAST
TRANSMITTED
I FRAME
1
TEI
4
TEI
ASSIGNED
TRANSMIT
ENQUIRY
UNASSIGNED
MODE NAM
V(S) = V(S) - 1
P = 1
ITD02376
5
AWAITING
ESTABLISHM.
TX I
COMMAND
V(S) = V(S) + 1
CLEAR
ACKNOWLEDGE
PENDING
START T200
RC = RC + 1
8
TIMER
RECOVERY
Figure 25b
Semiconductor Group
80
Functional Description
8
TIMER
RECOVERY
RME
RME
RME
SABME
RHCR:
DISC
UA
RHCR:
RHCR:
MDL-ERROR
INDICATION
(C, D)
DISCARD
I QUEUE
F = P
TX UA
8
STORE
STAR2:
WFA
TIMER
RECOVERY
F = P
XFIFO
CMDR XTF
CLEAR
TX UA
EXCEPTION
CONDITIONS
XFIFO
CMDR XTF
MDL-ERROR
INDICATION
(F)
DL-RELEASE
INDICATION
V(S) = V(A)
YES
STOP T200
STAR2:WFA = 0
NO
MODE NAM
4
TEI
ASSIGNED
DISCARD
I QUEUE
DL
ESTABLISH
INDICATION
STOP T200
START T203
CMDR:RHR;XRES
V(S) = 0
V(A) = 0
V(R) = 0
7
MULTIPLE
FRAME
ESTABLISHED
STAR2:TREC
ITD02377
Figure 25c
Semiconductor Group
81
Functional Description
8
TIMER
RECOVERY
RME
SET OWN
RECEIVER
BUSY
CLEAR OWN
RECEIVER
BUSY
DM
RHCR:
CLEAR
RECEIVER
BUSY
OWN
NO
F = 1
YES
YES
RECEIVER
RHCR
BUSY
NO
NO
YES
SET OWN
RECEIVER
BUSY
CLEAR OWN
RECEIVER
BUSY
MDL-ERROR
INDICATION
(E)
MDL-ERROR
INDICATION
(B)
CMDR:RNR = 1
STAR:XRNR
CMDR:RNR = 0
STAR:XRNR
ESTABLISH
DATA LINK
F = 0
F = 0
CLEAR
LAYER 3
INITIATED
TX RR
RESPONSE
TX RNR
RESPONSE
MODE NAM
5
CLEAR
ACKNOWLEDGE
PENDING
CLEAR
ACKNOWLEDGE
PENDING
AWAITING
ESTABLISHM.
8
TIMER
RECOVERY
Note: These signals are generated outside of this SDL representation,
and may be generated by the connection management entity.
ITD02378
Figure 25d
Semiconductor Group
82
Functional Description
8
TIMER
RECOVERY
RR
REJ
RSC /
CLEAR PEER
RECEIVER
BUSY
STAR:RRNR
NO
COMMAND
YES
YES
F = 1
NO
NO
P = 1
YES
NO
_
_
<
<
V(A) N(R) V(S)
ENQUIRY
YES
RESPONSE
STAR2:SDET
XPR /
V(A) = N(R)
STAR2:WFA
NO
STOP T200
_
_
<
<
V(A) N(R) V(S)
YES
XPR /
PCE
XMR /
INVOKE
RETRANS-
MISSION
N(R) ERROR
RECOVERY
V(A) = N(R)
STAR2:WFA
MODE NAM
8
7
5
TIMER
RECOVERY
MULTIPLE
FRAME
ESTABLISHED
AWAITING
ESTABLISHM.
STAR2:TREC
ITD02867
Figure 25e
Semiconductor Group
83
Functional Description
8
TIMER
RECOVERY
RME
RNR
FRMR
RCHR:
RSC /
MDL-ERROR
INDICATION
(K)
BUSY
STAR:RRNR
NO
ESTABLISH
DATA LINK
COMMAND
YES
YES
F = 1
CLEAR
LAYER 3
INITIATED
NO
NO
NO
MODE NAM
_
_
<
<
P = 1
YES
V(A) N(R) V(S)
5
AWAITING
ESTABLISHM.
YES
XPR /
ENQUIRY
RESPONSE
V(A) = N(R)
STAR2:SDET
STAR2:WFA
NO
_
_
<
<
V(A) N(R) V(S)
RESTART T200
RC = 0
YES
XPR /
PCE
XMR /
N(R)
ERROR
RECOVERY
INVOKE
RETRANS-
MISSION
V(A) = N(R)
STAR2:WFA
MODE NAM
8
7
5
TIMER
RECOVERY
MULTIPLE
FRAME
ESTABLISHED
AWAITING
ESTABLISHM.
STAR2:TREC
ITD02380
Figure 25f
Semiconductor Group
84
Functional Description
8
TIMER
RECOVERY
I
COMMAND
OWN
RECEIVER
BUSY
YES
NO
NO
DISCARD
INFORMATION
N(S) = V(R)
YES
NO
DISCARD
INFORMATION
P = 1
V(R) = V(R) + 1
YES
NO
REJECT
EXCEPTION
CLEAR REJECT
EXCEPTION
NOTE 2
F = 1
YES
RME
DL-DATA
INDICATION
NO
SET
REJECT
P = 1
TX RNR
RFIFO, RHCR
EXCEPTION
STAR2:SDET
YES
YES
YES
CLEAR
ACKNOWLEDGE
PENDING
P = 1
NO
F = P
ACKNOWLEDGE
PENDING
F = P
TX REJ
STAR2:SDET
NO
CLEAR
ACKNOWLEDGE
PENDING
ACKNOWLEDGE
PENDING
TX RR
STAR2:SDET
NOTE 1
SET
CLEAR
ACKNOWLEDGE
PENDING
ACKNOWLEDGE
PENDING
ITD03485
4
Figure 25h
Note 1: Processing of acknowledge pending is descripted on figure 25i
Note 2: This SDL representation does not include the optional procedure in Appendix I.
Figure 25g
Semiconductor Group
85
Functional Description
4
NO
_
_
<
<
V(A) N(R) V(S)
YES
XPR /
PCE
N(R)
V(A) = N(R)
ERROR
RECOVERY
STAR2:WFA
MODE NAM
8
5
TIMER
RECOVERY
AWAITING
ESTABLISHM.
ITD02382
Figure 25h
8
TIMER
RECOVERY
ACKNOWLEDGE
PENDING
NO
ACKNOWLEDGE
PENDING
YES
CLEAR
ACKNOWLEDGE
PENDING
F = 0
TX RR
STAR2:SDET
8
TIMER
RECOVERY
ITD02383
Figure 25i
Semiconductor Group
86
Functional Description
RELEVANT
STATES
(NOTE 1)
RME
DL
UI
FRAME
QUEUED UP
UI COMMAND
UNIT DATA
REQUEST
RHCR
REMOVE UI
FRAME FROM
QUEUE
DL
PLACE IN
UI QUEUE
UNIT DATA
INDICATION
UI
FRAME
P = 0
NOTE 2
QUEUED UP
TX UI
COMMAND
NOTE 2
XFIFO
CMDR: XTF
NOTE 2
Note 1: The relevant states are as follows
4 TEI-assigned
5 Awaiting-establishement
6 Awaiting-release
7 Multiple-frame-established
8 Timer-recovery
Note 2: The data link layer returns to the state it was in prior to the events shown.
ITD02384
Figure 26a
Semiconductor Group
87
Functional Description
RELEVANT
STATES
(NOTE 1)
CONTROL
FIELD
ERROR (W)
INFO NOT
PERMITTED
(X)
INCORRECT
LENGHT
(X)
1 FRAME
TOO LONG
(Y)
PCE /
MDL-ERROR
INDICATION
(L,M,N,O)
ESTABLISH
DATA LINK
CLEAR
LAYER 3
INITIATED
5
AWAITING
ESTABLISHM.
Note 1: The relevant states are as follows
7 Multiple-frame-established
8 Timer-recovery
ITD02385
Figure 26b
Semiconductor Group
88
Functional Description
N(R)
ERROR
RECOVERY
CLEAR
EXCEPTION
CONDITIONS
ESTABLISH
DATA LINK
TRANSMIT
ENQUIRY
CMDR:RHR,XRES
CLEAR
MDL-ERROR
INDICATION(J)
EXCEPTION
CLEAR PEER
RECEIVER
BUSY
P = 1
CONDITION
CMDR:RHR,XRES
MODE: NAM
PCE
CLEAR
REJECT
EXCEPTION
OWN
RECEIVER
BUSY
YES
ESTABLISH
DATA LINK
RC = 0
P = 1
NO
CLEAR
LAYER 3
INITIATED
CLEAR OWN
RECEIVER
BUSY
TX SABME
TX RR
COMMAND
TX RNR
COMMAND
XFIFO
CMDR:XTF
CMDR:RNR = 0
CLEAR
ACKNOWLEDGE
PENDING
RESTART T200
STOP T203
CLEAR
ACKNOWLEDGE
PENDING
START T200
ITD02386
Figure 26c
Semiconductor Group
89
Functional Description
INVOKE
RETRANS-
MISSION
ENQUIRY
RESPONSE
YES
F = 1
V(S) = N(R)
NO
XMR
OWN
RECEIVER
BUSY
YES
V(S) =V(S) - 1
NO
TX RR
TX RNR
I FRAME
RESPONSE
RESPONSE
QUEUED UP
STAR2:SDET
STAR2:SDET
NOTE
CLEAR
ACKNOWLEDGE
PENDING
BACK TRACK
ALONG
I QUEUE
Note: The generation of the correct number of signals in order to cause the required
.
retransmission of I frames does not alter their sequence integrity
ITD02387
Figure 26d
Semiconductor Group
90
Operational Description
3
Operational Description
3.1 Microprocessor Interface Operation
The ICC microcontroller interface can be selected to be either of the
(1) – Motorola type with control signals CS, R/W, DS 1)
(2) – Siemens/Intel non-multiplexed bus type with control signals CS, WR, DS 1)
(3) – or of the Siemens/Intel multiplexed address/data bus type with control signals
CS, WR, RD, ALE
The selection is performed via pin ALE as follows:
ALE tied to V DD
ALE tied to V SS
Edge on ALE
(1)
(2)
(3).
The occurrence of an edge on ALE, either positive or negative, at any time during the operation
immediately selects interface type (3). A return to one of the other interface types is possible
only if a hardware reset is issued.
3.2 Reset
After a hardware reset (pin RES), the ICC is in an idle state, and its registers are loaded with
specified values. A subset of ICC registers with defined reset values is listed in table 9.
During the reset pulse pins SDAX/SDS1 and SCA/FSD/SDS2 are “low”, all other pins are in
high impedance state.
1) Note:
These µp-interface-modes only make sense for a 28 pin package, as the address pins
are needed.The multifunctional pins SDAR and SIP are automatically interpreted as
A2 and A5 resp. and should therefore not be used for SSI or SLD interface or
terminal specific functions.
Semiconductor Group
91
Operational Description
Table 9
State of ICC Registers after Hardware Reset
Register
Value after
Reset (hex)
Meaning
ISTA
00
no interrupts
MASK
EXIR
STAR
00
all interrupts enabled
no interrupts
00
48 (4A)
- XFIFO is ready to be written to
- RFIFO is ready to receive at least 16 octets of a new
message
CMDR
MODE
00
00
no command
- auto mode
- 1-octet address field
- external timer mode
- receiver inactive
- IOM-1 interface, MONITOR channel used for TIC bus
access only
RBCL
RBCH
00
- no frame bytes received
XXX000002
SPCR
00
- IDP1 pin = “High”
- SIP pin “High impedance”
- Timing mode 0
- IOM interface test loop deactivated
- SLD B channel loop selected
- SDAX/SDS1, SCA/FSD/SDS2 pins = “Low”
CIRR/CIR0
CIXR/CIX0
7C
BF
- another device occupies the D and C/I channels
- received C/I code = “1111”
- no C/I code change
- TIC bus is not requested for transmitting a C/I code
- transmitted C/I code = “1111”
- T, E = logical “1”
STCR
00
- terminal specific functions disabled
- TIC bus address = “0000”
- no synchronous transfer
ADF1
ADF2
00
00
- inter-frame time fill = continuous “1”
- IOM-1 interface mode selected
- SDS1/2 low
Semiconductor Group
92
Operational Description
3.3 Initialization
During initialization a subset of registers have to be programmed to set the configuration
parameters according to the application and desired features. They are listed in table 10.
In table 10 the ISDN applications are denoted using the following abbreviations:
TE
Terminal Equipment TE1, TA
e.g. ISDN feature telephone
ISDN voice/data workstation
Terminal Adaptor for non-ISDN terminals (TE2)
LT
Line Termination
NT
Intelligent Network Termination
Table 10
Configuration Parameters for Initialization
Register
Bit
Effect
Application Restricted to
ADF 2
IMS
Program IOM-1 or IOM-2
interface mode
D2C2-0 Polarity of SDS2/1 (and/or
D1C2-0 selection of HDLC channel)
IOM-2
IOM-2
ODS
IOM output driver
tri-state/open drain
SPCR
(note)
SPU
Pull IDP1 low (to request
clocking from layer-1 device).
TE
IOM
SAC
SPM
SLD port inactive/active
IOM-1
IOM-1
0 Timing mode 0
1 Timing mode 1
TE/NT
LT only
0 Terminal timing mode
1 Non-terminal timing mode
TE
LT
IOM-2
TLP
Serial port B-test loop
C2C1-0 B-channel switching
C1C1-0 or
IOM-1
IOM-2
B/IC channel connect
Semiconductor Group
93
Operational Description
Configuration Parameters for Initialization (cont’d)
Register
Bit
Effect
Application
Restricted to
MODE
DIM2-0
IOM interface configuration for
D + C/I channel arbitration
Stop/Go bit monitoring for
HDLC transmission yes/no
HDLC interface
IOM
IOM
characteristics
Serial HDLC
HDLC
communication
ADF1
IDC
IOM Data Port IDP1,0
direction control
IOM-2
CSEL2-0 IOM channel select (Time slot) non-TE
IOM-2
IOM
CIXR/CIX0
STCR
RSS
Hardware reset generated by
either subscriber/exchange
awake or watchdog timer
TE specific
functions
(TSF = 1)
TSF
Terminal specific function
enable/SLD interface enable
IOM
IOM
TBA2-0
TIC bus address
Bus
configuration
for D+C/I (TIC)
MODE
TIMR
MDS2-0 HDLC message transfer mode 2
octet/(1 octet) address
TMD
Timer mode external/internal
Auto mode only
Auto mode only
CNT
VALUE
N1 and T1 in internal timer
mode (TMD = 1)
T2 in external timer mode
XAD1
XAD2
SAPI, TEI
Transmit frame address
SAPI1/2
TEI1/2
Receive SAPI, TEI address
values for internal address
recognition
Note: After a hardware reset the pins SDAX/SDS1 and SCA/FSD/SDS2 are both “low” and
have the functions of SDS1 and SDS2 in terminal timing mode (since SPM = 0),
respectively, until the SPCR is written to for the first time. From that moment on, the
function taken on by these pins depends on the state of IOM Mode Select bit IMS (ADF2
register).
Semiconductor Group
94
Operational Description
3.4 IOM® Interface Connections
IOM®-1
In IOM-1 interface mode
– pin IDP0 carries B channel, MONITOR, D and C/I data from layer 1 to layer 2
– pin IDP1 carries B channel, MONITOR, D and C/I data from layer 2 to layer 1.
IDP1 is an open drain output. The B channels can be set inactive (FFH) by setting the B
channel connect bits C1C1-0 and C2C1-0 in SPCR register to 0 (SLD loop), which is the state
after a hardware reset.
The MONITOR channel is inactive (FFH) if:
– no MONITOR channel transfer is programmed
– and the TIC bus (i.e. the fourth octet of IOM frame: D and C/I channels) is not accessed.
IOM®-2
Because of the enhanced communication capabilities offered by the IOM-2, e.g. for the control
of peripheral devices via the MONITOR channel, the direction of IDP0 and IDP1 is
programmable.
The type of the IOM output is selectable via bit ODS (ADF2) register. Thus, the driver is of the
open drain type if ODS = 0, and of the push-pull type when ODS = 1.
Non-Terminal Mode (SPM = 1)
Outside the programmed 4-byte subscriber channel (bits CSEL2-0, ADF1 register), both IDP1
and IDP0 are inactive.
Inside the programmed 4-byte subscriber channel:
– IDP1 carries the 2B+D channels as output toward the subscriber and the MONITOR and C/
I channel as output to the layer 1
– IDP1 is inactive during B1 and B2
– IDP0 carries the 2B + D channels coming from the subscriber line, and the MONITOR and
C/I channels from layer 1.
If IDC (IOM Direction Control, ADF1 register) is set to “1”, IDP0 sends the MONITOR, D and
C/I channels normally carried by IDP1, i.e. normally destined to the subscriber. This feature
can be used for test purposes, e.g. to send the D channel towards the system instead of the
subscriber. See figure 27.
Semiconductor Group
95
Operational Description
(a) IDC = 0
IDP0
M M
B1
B1
B2
B2
MONITOR
MONITOR
D
C/I
C/I
R
X
1
1
From Layer
ICC Idle
From Layer
ICC Receives
M M
D
IDP1
R
X
1
2
To Layer
ICC Idle
From Layer
ICC Transmits
(b) IDC = 1
IDP0
M
R
M
X
B1
B1
B2
B2
MONITOR
MONITOR
D
From Layer
C/I
C/I
1
2
From Layer
ICC Idle
ICC Transmits
M
X
M
R
D
IDP1
1
2
To Layer
ICC Idle
To Layer
ITD02868
ICC Receives
Not Sending (high impendance or open drain "1")
Figure 27
IOM® Data Ports 0, 1 in Non-Terminal Mode (SPM = 1)
Terminal Mode (SPM = 0)
In this case the IOM has the12-byte frame structure consisting of channels 0, 1, and 2 (see
figure 11):
– IDP0 carries the 2B + D channels from the subscriber line, and the MONITOR 0 and C/I 0
channels coming from layer 1;
– IDP1 carries the MONITOR 0 and C/I 0 channels to the layer 1.
Channel 1 of the IOM interface is used for internal communication in terminal applications. Two
cases have to be distinguished, according to whether the ICC is operated as a master device
(communication with slave devices via MONITOR 1 and C/I 1), or as a slave device
(communication with one master via MONITOR 1 and C/I 1).
Semiconductor Group
96
Operational Description
2B+ D
2B+ D
MON0,C/I0
MON0,C/I0
MON1,C/I1
MON1,C/I1
IDP0
IDP1
V/D Module
L1
ICC
Master
ITS02873
ISDN
Basic
Access
Interface
(a) ICC Master Mode (IDC = 0)
CH0
CH1
CH2
IDP0
B1
B2
MON0 D C/I0
IC1
IC2
MON1 C/I1
From
Layer 1
From
Layer 1
IC Transmit
if Prog.
To V/D
Modules
D-Channel
State
IDP1
B1
B2
MON0 D C/I0
To
Layer 1
To
Layer 1
TIC-Bus
Arbitration
ITD02875
Figure 28a
IOM® Data Ports 0, 1 in Terminal Mode (SPM = 0)
Semiconductor Group
97
Operational Description
2B+ D
2B+ D
MON0, C/I0,
MON1, C/I1
MON0, C/I0,
MON1, C/I1
IDP0
IDP1
L1
Master
ICC
Slave
ITS02874
ISDN
Basic
Access
Interface
(b) ICC Slave Mode (IDC = 1)
CH0
CH1
CH2
IDP0
B1
B2
MON0 D C/I0
From
Layer 1
From
Layer 1
D-Channel
State
IDP1
B1
B2
MON0 D C/I0
IC1
IC2
MON1 C/I1
To
Layer 1
To
Layer 1
IC Transmit
if Prog.
To V/D
Modules
TIC-Bus
Arbitration
ITD02876
Figure 28b
IOM® Data Ports 0, 1 in Terminal Mode (SPM = 0)
Semiconductor Group
98
Operational Description
If IDC is set to “0” (Master Mode):
– IDP0 carries the MONITOR 1 and C/I 1 channels as output to peripheral (voice/data)
devices;
– IPD0 carries the IC channels as output to other devices, if programmed (CxC1-0 = 01 in
register SPCR).
If IDC is set to “1” (Slave mode):
– IDP1 carries the MONITOR 1 and C/I 1 channels as output to a master device;
– IPD0 carries the IC channels as output to other devices, if programmed (CxC1-0 = 01 in
register SPCR).
If required (cf. DIM2-0, MODE register), bit 5 of the last byte in channel 2 on IDP0 is used to
indicate the D-channel state (Stop/Go bit) on and bits 2 to 5 of the last byte are used for TIC
bus access arbitration.
Figure 28 shows the connections in a multifunctional terminal with the ICC as a master
(figure 28a) or a slave device (figure 28b).
Semiconductor Group
99
Operational Description
3.5 Processing
3.5.1 Interrupt Structure
Since the ICC provides only one interrupt request output (INT), the cause of an interrupt is
determined by the microprocessor by reading the Interrupt Status Register ISTA. In this
register, seven interrupt sources can be directly read. The LSB of ISTA points to eight non-
critical interrupt sources which are indicated in the Extended Interrupt Register EXIR
(figure 29).
INT
ICC
ISTA RME RPF RSC XPR TIN CIC SIN EXI
MASK
EXIR XMR XDU PCE RFO SOV MOS SAW WOV
ITD02869
Figure 29
ICC Interrupt Structure
A read of the ISTA register clears all bits except EXI and CIC. CIC is cleared by reading CIRR/
CIR0. A read of EXIR clears the EXI bit in ISTA as well as the EXIR register.
When all bits in ISTA are cleared, the interrupt line (INT) is deactivated.
Each interrupt source in ISTA register can be selectively masked by setting to “1” the
corresponding bit in MASK. Masked interrupt status bits are not indicated when ISTA is read.
Instead, they remain internally stored and pending, until the mask bit is reset to zero. Reading
the ISTA while a mask bit is active has no effect on the pending interrupt.
In the event of an extended interrupt EXIR, EXI is set even when the corresponding mask bit
in MASK is active, but no interrupt (INT) is generated. In the event of a C/I channel interrupt
CIC is set, even when the corresponding mask bit in MASK is active, but no interrupt (INT) is
generated.
Except for CIC and MOS all interrupt sources are directly determined by a read of ISTA and
(possibly) EXIR.
Semiconductor Group
100
Operational Description
Figure 30 shows the CIC and MOS interrupt logic.
CIC Interrupt Logic
A CIC interrupt may originate
– from a change in received C/I channel (0) code (CIC0)
or (in the case of IOM-2 terminal mode only)
– from a change in received C/I channel 1 code (CIC 1).
The two corresponding status bits CIC0 and CIC1 are read in CIR0 register. CIC1 can be
individually disabled by clearing the enable bit CI1E (ADF1 register). In this case the
occurrence of a code change in CIR1 will not be displayed by CIC1 until the corresponding
enable bit has been set to one.
Bits CIC0 and CIC1 are cleared by a read of CIR0.
An interrupt status is indicated every time a valid new code is loaded in CIR0 or CIR1. But in
the case of a code change, the new code is not loaded until the previous contents have been
read. When this is done and a second code change has already occurred, a new interrupt is
immediately generated and the new code replaces the previous one in the register. The code
registers are buffered with a FIFO size of two. Thus, if several consecutive codes are detected,
only the first and the last code is obtained at the first and second register read, respectively.
Semiconductor Group
101
Operational Description
(a)
C/I0 Code
C/I1 Code
C
O
D
R
1
CIR1
CI1E ADF1
CIRO
BAS
C
O
D
R
O
CIC0 CIC1
ISTA
CIC
MASK
INT
(b)
MOR1
MOX1
MOR0
MOX0
MOCR MRE1 MRC1
MOSR MDR1
MIE1
MER1 MDA1 MAB1
MRE0 MRC0
MDR0
MIE0
MER0 MDA0 MAB0
EXIR MOS
ISTA
EXI
MASK
ITD02870
INT
Figure 30
a) CIC Interrupt Structure
b) MOS Interrupt Structure (IOM®-2 Mode)
Semiconductor Group
102
Operational Description
MOS Interrupt Logic
The MOS interrupt logic shown in figure 30 is valid only in the case of IOM-2 interface mode.
Further, only one MONITOR channel is handled in the case of IOM-2 non-terminal timing
modes. In this case, MOR1 and MOX1 are unused.
The MONITOR Data Receive interrupt status MDR has two enable bits, MONITOR Receive
interrupt Enable (MRE) and MR bit Control (MRC). The MONITOR channel End of Reception
MER, MONITOR channel Data Acknowledged MDA and MONITOR channel Data Abort MAB
interrupt status bits have a common enable bit MONITOR Interrupt Enable MIE.
MRE prevents the occurrence of MDR status, including when the first byte of a packet is
received. When MRE is active (1) but MRC is inactive, the MDR interrupt status is generated
only for the first byte of a receive packet. When both MRE and MRC are active, MDR is always
generated and all received MONITOR bytes - marked by a 1-to-0 transition in MX bit - are
stored. (Additionally, an active MRC enables the control of the MR handshake bit according to
the MONITOR channel protocol.)
In IOM-1 mode the reception of a MONITOR byte is directly indicated by MOS interrupt status,
and registers MOCR and MOSR are not used.
3.5.2 Data Transfer
The control of the data transfer phase is mainly done by commands from the µP to ICC via the
Command Register (CMDR).
Table 11 gives a summary of possible interrupts from the HDLC controller and the appropriate
reaction to these interrupts.
Table 12 lists the most important commands which are issued by a microprocessor by setting
one or more bits in CMDR.
The powerful FIFO logic, which consists of a 2 x 32 byte receive and a 2 x 32 byte transmit
FIFO, as well as an intelligent FIFO controller, builds a flexible interface to the upper protocol
layers implemented in the microcontroller.
The extent of LAPD protocol support is dependent on the selected message transfer mode,
see section 2.4.1.
Semiconductor Group
103
Operational Description
Table 11
Interrupts from ICC HDLC Controller
Mnemonic
Register Meaning
Reaction
Layer-2 Receive
RPF
ISTA
ISTA
Receive Pool Full. Request to
read received octets of an
uncompleted HDLC frame from
RFIFO.
Read 32 octets from RFIFO and
acknowledge with RMC.
RME
Receive Message End.
Read RFIFO (number of octets
Request to read received octets given by RBCL4-0) and status
of a complete HDLC frame (or information and acknowledge
the last part of a frame) from
RFIFO.
with RMC.
RFO
PCE
EXIR
EXIR
Receive Frame Overflow. A
complete frame has been lost
because storage space in
RFIFO was not available.
Error report for statistical
purposes. Possible cause:
deficiency in software.
Protocol Error. S or I frame with Link re-establishment.
incorrect N(R) or S frame with I Indication to layer 3.
field received (in auto mode
only).
Layer-2 Transmit
XPR
XMR
XDU
ISTA
Transmit Pool Ready. Further
octets of an HDLC frame can be the frame currently being
written to XFIFO.
If XIFC was issued (auto
mode), indicates that the
message was successfully
acknowledged with S frame.
Write data bytes in the XFIFO if
transmitted is not finished or a
new frame is to be transmitted,
and issue an XIF, XIFC, XTF or
XTFC command.
EXIR
EXIR
Transmit Message Repeat.
Frame must be repeated
Transmission of the frame must
be repeated. No indication to
because of a transmission error layer 3.
(all HDLC message transfer
modes) or a received negative
acknowledgement (auto mode
only) from peer station.
Transmit Data Underrun.
Frame has been aborted
because the XFIFO holds no
Transmission of the frame must
be repeated. Possible cause:
excessively long soft-
further data and XME (XIFC or ware reaction times.
XTFC) was not issued.
Semiconductor Group
104
Operational Description
Layer-2 Transmit (cont’d)
Mnemonic
Register Meaning
Reaction
RSC
ISTA
Receive Status Change. A
status change from peer station
has been received (RR or RNR
frame), auto mode only.
Stop sending new I frames.
TIN
ISTA
Timer Interrupt. External timer Link re-established. Indication
expired or, in auto mode,
to layer 3. (Auto mode)
internal timer (T200) and repeat
counter (N200) both expired.
Semiconductor Group
105
Operational Description
Table 12
List of Commands
Command
Mnemonic
HEX
Bit 7 … 0
Meaning
RMC
RRES
RNR
80
1000 0000 Receive Message Complete. Acknowledges a
block (RPF) or a frame (RME) stored in the
RFIFO).
40
20
0100 0000 Reset HDLC Receiver. The RFIFIO is cleared.
the transmit and receive counters (V(S), V(R)) are
reset (auto mode).
0010 0000 Receiver Not Ready (auto mode). An I or S
frame will be acknowledged with RNR frame.
STI
10
0A
0001 0000 Start Timer.
XTFC
0000 1010 Transmit Transparent Frame and Close.
Enables the “transparent” transmission of the
block entered last in the XFIFO. The frame is
closed with a CRC and a flag.
XIFC
06
0000 0110 Transmit I Frame and Close. Enables the “auto
mode” transmission of the block entered last in the
XFIFO. The frame is closed with a CRC and a flag.
XTF
XIF
08
04
01
0000 1000 Transmit Transparent Frame. Enables the
“transparent” transmission of the block entered
last in the XFIFO without closing the frame.
0000 0100 Transmit I Frame. Enables the “auto mode”
transmission of the block entered last in the
XFIFO without closing the frame.
XRES
0000 0001 Reset HDLC Transmitter. The XFIFO is cleared.
Semiconductor Group
106
Operational Description
3.5.2.1HDLC Frame Reception
Assuming a normally running communication link (layer 1 activated, layer 2 link established),
figure 31 illustrates the transfer of an I frame. The transmitter is shown on the left and the
receiver on the right, with the interaction between the microcontroller system and the ICC in
terms of interrupt and command stimuli.
When the frame (excluding the CRC field) is not longer than 32 bytes, the whole frame is
transferred in one block. The reception of the frame is reported via the Receive Message End
(RME) interrupt. The number of bytes stored in RFIFO can be read out from RBCL. The
Receive Status Register (RSTA) includes information about the frame, such as frame aborted
yes/no or CRC valid yes/no and, if complete or partial address recognition is selected, the
identification of the frame address.
Depending on the HDLC message transfer mode, the address and control field of the frame
can be read from auxiliary registers (SAPR and RHCR), as shown in figure 32.
LAPD Link
RPF
RMC
RPF
µC-
System
µC-
System
ICC
ICC
RMC
RME
RMC
ITD02871
:
= Data Transfer
*)
In Auto Mode the "RR" Response will be Transmitted Autonomously
Figure 31
Transmission of an I Frame in the D Channel (Subscriber to Exchange)
Note 1 Only if a 2-byte address field is defined (MDS0 = 1 in MODE register).
Semiconductor Group
107
Operational Description
Address
High
Address
Low
Flag
Control
Information
CRC
Flag
Auto-Mode
(U and I frames)
SAP1,SAP2
FE,FC
TEI1,TEI2
FF
RHCR
RFIFO
RFIFO
RFIFO
RSTA
RSTA
RSTA
RSTA
RSTA
(Note 1)
(Note 2)
(Note 3)
Non-Auto
Mode
SAP1,SAP2
FE,FC
TEI1,TEI2
FF
RHCR
(Note 1)
(Note 2)
(Note 4)
Transparent
Mode 1
TEI1,TEI2
FF
SAPR
SAPR
RFIFO
RFIFO
Transparent
Mode 2
Transparent
Mode 3
SAP1,SAP2
FE,FC
ITD02872
Description of Symbols:
Checked automatically by ICC
Compared with register or fixed value
Stored into register or RFIFO
Figure 32
Receive Data Flow
Note 2 Comparison with group TEI (FFH) is only made if a 2-byte address field is defined
MDS0 = 1 in MODE register).
Note 3 In the case of an extended, modulo 128 control field format (MCS = 1 in SAP2 register)
the control field is stored in RHCR in compressed form (I frames).
Note 4 In the case of extended control field, only the first byte is stored in RHCR, the second
in RFIFO.
Semiconductor Group
108
Operational Description
A frame longer than 32 bytes is transferred to the microcontroller in blocks of 32 bytes plus one
remainder of length 1 to 32 bytes. The reception of a 32-byte block is reported by a Receive
Pool Full (RPF) interrupt and the data in RFIFO remains valid until this interrupt is
acknowledged (RMC). This process is repeated until the reception of the remainder block is
completed, as reported by RME (figure 31). If the second RFIFO pool has been filled or an
end-of frame is received while a previous RPF or RME interrupt is not yet acknowledged by
RMC, the corresponding interrupt will be generated only when RMC has been issued. When
RME has been indicated, bits 0-4 of the RBCL register represent the number of bytes stored
in the RFIFO. Bits 7 to 5 of RBCL and bits 0 to 3 of RBCH indicate the total number of 32-byte
blocks which where stored until the reception of the remainder block. When the total frame
length exceeds 4095 bytes, bit OV (RBCH) is set but the counter is not blocked.
The contents of RBCL, RBCH and RSTA registers are valid only after the occurrence of the
RME interrupt, and remain valid until the microprocessor issues an acknowledgment (RMC).
The contents of RHCR and/or SAPR, also remain valid until acknowledgment.
If a frame could not be stored due to a full RFIFO, the microcontroller is informed of this via the
Receive Frame Overflow interrupt (RFO).
3.5.2.2HDLC Frame Transmission
After the XFIFO status has been checked by polling the Transmit FIFO Write Enable (XFW) bit
or after a Transmit Pool Ready (XPR) interrupt, up to 32 bytes may be entered in XFIFO.
Transmission of an HDLC frame is started when a transmit command (see table 12) is issued.
The opening flag is generated automatically. In the case of an auto mode transmission (XIF or
XIFC), the control field is also generated by the ICC, and the contents of register XAD1 (and,
for LAPD, XAD2) are transmitted as the address, as shown in figure 33.
Semiconductor Group
109
Operational Description
* Transmit
Transparent
Frame
XFIFO
* Transmit
I Frame
(auto-mode only!)
XAD1
XAD2
XFIFO
Transmitted
HDLC Frame
Address
High
Address
Low
Flag
Control
INFORMATION
CRC
Flag
If 2 byte
address
field
Appended if CPU
has issued
transmit message
end (XME)
selected
commend.
ITD02862
Description of Symbols:
Generated automatically by ICC
Written initially by CPU (into register)
Loaded (repeatedly) by CPU upon ICC request (XPR interrupt)
Figure 33
Transmit Data Flow
Semiconductor Group
110
Operational Description
The HDLC controller will request another data block by an XPR interrupt if there are no more
than 32 bytes in XFIFO and the frame close command bit (Transmit Message End XME) has
not been set. To this the microcontroller responds by writing another pool of data and re-
issuing a transmit command for that pool. When XME is set, all remaining bytes in XFIFO are
transmitted, the CRC field and the closing flag of the HDLC frame are appended and the
controller generates a new XPR interrupt.
The microcontroller does not necessarily have to transfer a frame in blocks of 32 bytes. As a
matter of fact, the sub-blocks issued by the microcontroller and separated by a transmit
command, can be between 0 and 32 bytes long.
If the XFIFO runs out of data and the XME command bit has not been set, the frame will be
terminated with an abort sequence (seven 1’s) followed by inter-frame time fill, and the
microcontroller will be advised by a Transmit Data Underrun (XDU) interrupt. An HDLC frame
may also be aborted by setting the Transmitter Reset (XRES) command bit.
Semiconductor Group
111
Register Description
4
Detailed Register Description
The parameterization of the ICC and the transfer of data and control information between the
µP and ICC is performed through two register sets.
The register set in the address range 00-2 BH pertains to the HDLC transceiver and LAPD con-
troller. It includes the two FIFOs having an identical address range from 00-1 FH.
The register set ranging from 30-3 AH pertains to the control of layer-1 functions and of the IOM
interface. Since the meaning of most register bits depends on the select IOM mode (IOM-1 or
IOM-2), the description of this register set is divided into two sections:
● Special Purpose Registers: IOM-1 mode
● Special Purpose Registers: IOM-2 mode
The address map and a register summary are shown in the following tables:
Table 13
ICC Address Map 00-2BH
Address Read
(hex)
Write
Name
Description
Name
Description
00
.
RFIFO
Receive FIFO
XFIFO
Transmit FIFO
.
1F
20
21
22
23
24
25
26
27
28
29
2A
2B
ISTA
Interrupt Status Register
Status Register
MASK
CMDR
Mask Register
STAR
MODE
TIMR
EXIR
Command Register
Mode Register
Timer Register
Extended Interrupt Register
Receive Frame Byte Count Low
Receive SAPI
XAD1
XAD2
SAP1
SAP2
TEI1
Transmit Address 1
Transmit Address 2
Individual SAPI 1
Individual SAPI 2
Individual TEI 1
RBCL
SAPR
RSTA
Receive Status Register
RHCR
RBCH
STAR2
Receive HDLC Control
Receive Frame Byte Count High
Status Register 2
TEI2
Individual TEI 2
Semiconcuctor Group
112
Register Description
Table 14
ICC Address Map 30-3AH
Address Read
(hex)
Write
Name
Name
Description
Description
30
31
SPCR
Serial Port Control Register
CIRR/
CIR0
Command /Indication Receive (0)
CIXR/
CIX0
Command/Indication Transmit (0)
MONITOR Transmit (0)
32
33
34
MOR/
MOR0
MONITOR Receive (0)
MOX/
MOX0
SSCR/
CIR1
SIP Signaling Code Receive
Command/Indication Receive 1
SSCX/
CIX1
SIP Signaling Code Transmit
Command/Indication Transmit 1
SFCR/
MOR1
SIP Feature Control Read/
MONITOR Receive 1
SFCW/
MOX1
SIP Feature Control Write/
MONITOR Transmit 1
35
36
37
38
39
3A
C1R
Channel Register 1
C2R
Channel Register 2
B1CR
B2CR
ADF2
MOSR
B1 Channel Register
B2 Channel Register
Additional Feature Register 2
MONITOR Status Register
STCR
ADF1
Sync Transfer Control Register
Additional Feature Register 1
MOCR
MONITOR Control Register
Semiconcuctor Group
113
Register Description
Table 15
Register Summary: HDLC Operation and Status Registers
20H
RME RPF
RSC
XPR
TIN
CIC
SIN
EXI
ISTA
MASK W
MAC0 STAR R
CMD
DIM2 DIM1 DIM0 MOD R/W
R
20H
21H
21H
XFW
XRNR RRNR MBR
MAC1 BVS
XIF XME
W
RMC RRES RNR
STI
XTF
XRES
22H
23H
24H
MDS1 MDS0 TMD
CONT
RAC
TIMR R/W
VAL-
MOS
EXIR
R
R
XMR XDU
PCE
RFO
SOV
SAW
WOV
XAD1
24H
25H
RBCL R
XAD2
SAPR R
RBC7 RBC6 RBC5 RBC4 RBC3 RBC2 RBC1 RBC0
25H
26H
26H
27H
27H
28H
29H
29H
2AH
2BH
W
SAPI1
CRC RAB
SAPI2
TEI1
CRI
0
SAP1
W
RSTA R
RDA RDO
SA1
SA0
C/R
TA
0
MCS
SAP2
TEI1
W
W
EA
RHCR R
TEI2
W
TEI2
OV
0
EA
XAC VN1
VN0
0
RBC1 RBC1 RBC9 RBC8 RHCR R
WFA TREC SDET STAR R
0
0
0
Semiconcuctor Group
114
Register Description
Table 16
Register Summary: Special Purpose Register IOM®-1 Mode
IOM®-1:
30H
SPU SAC
BAS
RSS BAC
SPM
TLP
CODR
CODX
C1C1 C1C0 C2C1 C2C0 SPCR R/W
31H
31H
32H
0
CIC0
TCX
0
CIRR
CIXR
MOR
R
ECX
W
R
32H
33H
MOX
W
SSCR R
SSCX W
SFCR R
33H
34H
34H
35H
36H
37H
37H
38H
38H
39H
SFC
C1R
C2R
W
R/W
R/W
B1CR R
STCR W
B2CR R
TSF
IMS
TBA2 TBA1 TBA0 ST1
ST0
SC1
SC0
WTC2 0
0
0
0
0
0
0
0
0
ITF
0
ADF1
W
0
0
ADF2 R/W
Semiconcuctor Group
115
Register Description
Table 17
Register Summary: Special Purpose Register IOM®-2 Mode
IOM®-2:
30H
SPU
0
0
SPM
TLP
C1C1 C1C0 C2C1 C2C0 SPCR R/W
31H
31H
32H
BAS
CODR0
CODX0
CIC0
1
CIC1
1
CIR0
CIX0
R
RSS BAC
W
MOR0 R
MOX0 W
32H
33hH
33hH
34H
CIR1
CIXR1
R
C
C
O
CODR1
CODX1
R
R
1
1
MR1
1MR1
MX1
1MX1
WR
MOR1 R
MOX1 W
34H
35H
36H
37H
37H
38H
38H
39H
3AH
3AH
C1R
C2R
R/W
R/W
B1CR R
STCR W
B2CR R
TSF
IMS
TBA2 TBA1 TBA0 ST1
ST0
SC1
SC0
WTC2 CI1E
IDC
CSEL CSEL CSEL ITF
ADF1
W
D2C2 D2C1 D2C0 ODS
D1C2 D1C1 D1C0 ADF2 R/W
MER1 MDA1 MAB1 MDR0 MER0 MDA0 MAB0 MOS
MRC1 MIE1 MXC1 MRE0 MRC0 MIE0 MXC0 MOC
R
W
Semiconcuctor Group
116
Register Description
4.1 HDLC Operation and Status Registers
4.1.1 Receive FIFO
RFIFO
Read
Address 00-1FH
A read access to any address within the range 00-1FH gives access to the “current” FIFO lo-
cation selected by an internal pointer which is automatically incremented after each read ac-
cess. This allows for the use of efficient “moving string” type commands by the processor.
The RFIFO contains up to 32 bytes of received frame.
After an ISTA:RPF interrupt, exactly 32 bytes are available.
After an ISTA:RME interrupt, the number of bytes available can be obtained by reading the
RBCL register.
4.1.2 Transmit FIFO
XFIFO
Write
Address 00-1FH
A write access to any address within the range 00-1FH gives access to the “current” FIFO lo-
cation selected by an internal pointer which is automatically incremented after each write ac-
cess. This allows for the use of efficient “move string” type commands by the processor.
Up to 32 bytes of transmit data can be written into the XFIFO following an ISTA:XPR interrupt.
4.1.3 Interrupt Status Register
ISTA
Read
Address 20H
Value after reset: 00H
7
0
RME RPF
RSC XPR
TIN
CIC
SIN
EXI
RME
RPF
Receive Message End
One complete frame of length less than or equal to 32 bytes, or the last part
of a frame of length greater than 32 bytes has been received. The contents
are available in the RFIFO. The message length and additional information
may be obtained from RBCH+RBCL and the RSTA register.
Receive Poll Full
A 32-byte block of a frame longer than 32 bytes has been received and is
available in the RFIFO. The frame is not yet complete.
Semiconcuctor Group
117
Register Description
RSC
XPR
Receive Status Change. Used in auto mode only.
A status change in the receiver of the remote station – Receiver
Ready/Receiver Not Ready - has been detected (RR or RNR S-frame).
The actual status of the remote station can be read from the STAR
register (RRNR bit).
Transmit Pool Ready
A data block of up to 32 bytes can be written to the XFIFO.
An XPR interrupt will be generated in the following cases:
– after an XTF or XIF command, when one transmit pool is emptied and
the frame is not yet complete
– after an XTF together with an XME command is issued, when the
whole transparent frame has been transmitted
– after an XIF together with an XME command is issued, when the
whole I frame has been transmitted and a positive acknowledgment from
the remote station has been received, (auto mode).
TIN
CIC
Timer Interrupt
The internal timer and repeat counter has expired (see TIMR register).
Channel Change
A change in C/I channel 0 or C/I channel 1 (only in IOM-2 TE mode)
has been recognized. The actual value can be read from CIR0 or CIR1.
SIN
Synchronous Transfer Interrupt
When programmed (STCR register), this interrupt is generated to enable
the processor to lock on to the IOM timing, for synchronous transfers.
EXI
Extended Interrupt
This bit indicates that one of six non-critical interrupts has been generated.
The exact interrupt cause can be read from EXIR.
Note:
A read of the ISTA register clears all bits except EXI and CISQ. EXI is
cleared by the reading of EXIR register, CISQ is cleared by reading
CIRR/CIR0.
Semiconcuctor Group
118
Register Description
4.1.4 Mask Register
MASK
Write
Address 20H
Value after reset: 00H
7
0
RME RPF
RSC XPR
TIN
CIC
SIN
EXI
Each interrupt source in the ISTA register can be selective masked by setting
to “1” the corresponding bit in MASK. Masked interrupt status bits are not
indicated when ISTA is read. Instead, they remain internally stored and
pending, until the mask bit is reset to zero.
Note: In the event of an extended interrupt and of a C/I or S/Q channel change,
EXI and CIC are set in ISTA even if the corresponding mask bits in MASK
are active, but no interrupt (INT pin) is generated.
4.1.5 Status Register
STAR
Read
Address 2H
Value after reset: 48H
7
0
XDOV XFW XRNR RRN
MBR MAC BVS MAC0
XDOV
XFW
Transmit Data Overflow
More than 32 bytes have been written in one pool of the XFIFO, i.e.
data has been overwritten.
Transmit FIFO Write Enable
Data can be written in the XFIFO. This bit may be polled instead of (or in
addition to) using the XPR interrupt.
XRNR
Transmit RNR. Used in auto mode only
In auto mode, this bit indicates whether the ICC-B receiver is in the “ready”
(0) or “not ready” (1) state. When “not ready”, the ICC-B sends an
RNR S-frame autonomously to the remote station when an I frame or an
S frame is received.
RRNR
Receive RNR. Used in auto mode only.
In the auto mode, this bit indicates whether the ICC-B has received an RR
or an RNR frame, this being an indication of the current state of the remote
station: receiver ready (0) or receiver not ready (1).
Semiconcuctor Group
119
Register Description
MBR
Message Buffer Ready
This bit signifies that temporary storage is available in the RFIFO to receive
at least the first 16 bytes of a new message.
MAC1
MONITOR Transmit Channel 1 Active (IOM-2 terminal mode only)
Data transmission is in progress in MONITOR channel 1.
BVS
B channel valid on SIP (IOM-1 mode only). B channel on SIP (SLD)
can be accessed.
MAC0
MONITOR Transmit Channel 0 Active. Used in IOM-2 mode only.
Data transmission is in progress in MONITOR channel 0.
4.1.6 Command Register
CMDR
Write
Address 2H
Value after reset: 00H
7
0
RMC RRE
RNR STI
XTF
XIF
XME XRES
Note: The maximum time between writing to the CMDR register and the execution
of the command is 2.5 DCL clock cycles. During this time no further
commands should be written to the CMDR register to avoid any loss of
commands.
RMC
Receive Message Complete
Reaction to RPF (Receive Pool Full) or RME (Receive Message End)
interrupt. By setting this bit, the processor confirms that it has fetched the
data, and indicates that the corresponding space in the RFIFO may be
released.
RRES
RNR
STI
Receiver Reset
HDLC receiver is reset, the RFIFO is cleared of any data.
In addition, in auto mode, the transmit and receive counters (V(S), V(R))
are reset.
Receiver Not Ready. Used in auto mode only.
Determines the state of the ICC-B HDLC receiver.
When RNR=“0”, a received I or S-frame is acknowledged by an RR
supervisory frame, otherwise by an RNR supervisory frame.
Start Timer.
The ICC-B hardware timer is started when STI is set to one. In the internal
timer mode (TMD bit, MODE register) an S Command (RR, RNR) with poll bit
set is transmitted in addition. The timer may be stopped by a write of the
TIMR register.
Semiconcuctor Group
120
Register Description
XTF
XIF
Transmit Transparent Frame
After having written up to 32 bytes in the XFIFO, the processor initiates
the transmission of a transparent frame by setting this bit to “1”. The
opening flag is automatically added to the message by the ICC-B.
Transmit I Frame. Used in auto mode only
After having written up to 32 bytes in the XFIFO, the processor initiates
the transmission of an I frame by setting this bit to “1”. The opening flag,
the address and the control field are automatically added by the ICC-B.
XME
Transmit Message End
By setting this bit to “1” the processor indicates that the data block written last
in the XFIFO complete the corresponding frame. The ICC-B terminates
the transmission by appending the CRC and the closing flag sequence
to the data.
XRES
Transmitter Reset
HDLC transmitter is reset and the XFIFO is cleared of any data.
This command can be used by the processor to abort a frame
currently in transmission.
Notes: ● After an XPR interrupt further data has been written in the
XFIFO and the appropriate Transmit Command (XTF or XIF) has
to be written in the CMDR register again to continue transmission,
when the current frame is not yet complete (see also XPR in ISTA).
●
During frame transmission, the 0-bit insertion according
to the HDLC bit-stuffing mechanism is done automatically.
4.1.7 Mode Register
MODE
Read/Write
Address 22H
Value after reset: 00H
7
0
MDS MDS MDS TMD RAC DIM2 DIM1 DIM0
MDS2-0
Mode Select
Determines the message transfer mode of the HDLC controller,
as follows:
Semiconcuctor Group
121
Register Description
Number
of
Address
Bytes
MDS2
MDS1
MDS0
Mode
Address Comparison
1.Byte 2.Byte
Remark
Auto mode
TEI1,TEI2
–
0
0
0
1
One-byte address
compare. HDLC proto-
col handling for frames
with address TEI1
Auto mode
SAP1,SAP2,SAPG
TEI1,TEI2,TEIG
0
1
0
2
Two-byte address com-
pare. LAPD protocol
handling for frames
with address SAP1 +
TEI1
Non-Auto
mode
TEI1,TEI2
–
0
0
1
1
0
0
1
1
1
2
One-byte address
compare.
Non-Auto
mode
SAP1,SAP2,SAPG
TEI1,TEI2,TEIG
0
1
Two-byte address
compare.
Reserved
1
0
Transparent
mode 1
–
TEI1,TEI2,TEIG
1
1
>1
–
Low-byte address com-
pare.
Transparent
mode 2
–
–
–
1
0
No address compare.
All frames accepted.
Transparent
mode 3
SAP1,SAP2,SAPG
1
1
>1
High-byte address
compare.
Note:
TMD
SAP1, SAP2: two programmable address values for the first received
address byte (in the case of an address field longer than 1 byte);
SAPG = fixed value FC / FEH.
TEI1, TEI2: two programmable address values for the second (or the only,
in the case of a one-byte address) received address byte;
TEIG = fixed value FFH.
Timer Mode
Sets the operating mode of the ICC-B timer. In the external mode (0) the
timer is controlled by the processor. It is started by setting the STI bit in
CMDR and it is stopped by a write of the TIMR register.
In the internal mode (1) the timer is used internally by the ICC-B for timeout
and retry conditions (handling of LAPD/HDLC protocol in auto mode).
Semiconcuctor Group
122
Register Description
RAC
Receiver Active
The HDLC receiver is activated when this bit is set to “1”.
DIM2-0
Digital Interface Mode
These bits define the characteristics of the IOM Data Ports (IDP0, IDP1)
according to following tables:
IOM®-1 Modes (ADF2:IMS = 0)
DIM2-0
Characteristics
0
1
2
3
4
5-7
IOM frame structure
x
x
x
x
HDLC interface
x
MONITOR channel
used for TIC
x
x
x
x
x
x
bus access 1)
MONITOR channel
used for data transfer
x
x
MONITOR channel
stop/go bit evaluated
for D-channel
access handling 2)
Reserved
x
1)
Notes:
If the TIC bus access handling is not required, i.e. if only one layer-2
device occupies the D and C/I channel, the TIC bus address should be
programmed to “111” e.g. STCR = 70H.
2)
This function must be selected if the ICC controls an S layer-1 device
(SBC PEB 2080) in a TE configuration.
Semiconcuctor Group
123
Register Description
IOM®-2 Modes (ADF2:IMS = 1)
Characteristics
0
1
2
3
4-7
IOM -2 terminal mode
SPCR:SPM = 0
x
x
x
x
IOM -2 non-terminal mode
SPCR:SPM = 1
x
x
x
Last octet of IOM channel 2
used for TIC bus access
x
x
x
Stop/go bit evaluated for
D-channel access handling1)
Reserved
x
1)
Note:
This function must be selected if the ICC controls an S layer-1 device
(SBCX PEB 2081) in a TE configuration.
4.1.8 Timer Register
TIMR
Read/Write
Address 23H
Value after reset: undefined (previous value)
7
0
CONT
VALUE
CNT
The meaning depends on the selected timer mode (TMD bit, MODE register).
* Internal Timer Mode (TMD = 1)
CNT indicates the maximum number of S commands “N1” which are
transmitted autonomously by the ICC after expiration of time period T1
(retry, according to HDLC).
Semiconcuctor Group
124
Register Description
The internal timer procedure will be started in auto mode:
– after start of an I-frame transmission
or
– after an “RNR” S frame has been received.
After the last retry, a timer interrupt (TIN-bit in ISTA) is generated.
The timer procedure will be stopped when
– a TIN interrupt is generated. The time between the start of an I-frame
transmission or reception of an “RNR” S frame and the generation of a
TIN interrupt is equal to: (CNT + 1) x T1.
– or the TIMR is written
– or a positive or negative acknowledgement has been received.
Note: The maximum value of CNT can be 6. If CNT is set to 7, the number
of retries is unlimited.
* External Timer Mode (TMD = 0)
CNT together with VALUE determine the time period T2 after which
a TIN interrupt will be generated:
CNT x 2.048 s + T1
with T1 = (VALUE + 1) x 0.064 s,
in the normal case, and
T2 = 16348 x CNT x DCL + T1
with T1 = 512 x (VALUE + 1) x DCL
when TLP = 1 (test loop activated, SPCR register).
DCL denotes the period of the DCL clock.
The timer can be started by setting the STI-bit in CMDR and will be
stopped when a TIN interrupt is generated or the TIMR register is written.
Note: If CNT is set to 7, a TIN interrupt is indefinitely generated after
every expiration of T1.f
VALUE
Determines the time period T1:
T1 = (VALUE + 1) x 0.064 s (SPCR:TLP = 0, normal mode)
T1 = 512 x (VALUE + 1) x DCL (SPCR:TLP = 1, test mode).
Semiconcuctor Group
125
Register Description
4.1.9 Extended Interrupt Register
EXIR
Read
Address 24H
Value after reset: 00H.
7
0
XMR XDU PCE
RFO SOV MOS SAW WOV
XMR
XDU
Transmit Message Repeat
The transmission of the last frame has to be repeated because:
– the ICC-B has received a negative acknowledgment to an I frame in
auto mode (according to HDLC/LAPD)
– or a collision on the S bus has been detected after the 32nd data byte
of a transmit frame.
Transmit Data Underrun
The current transmission of a frame is aborted by transmitting seven “1’s”
because the XFIFO holds no further data. This interrupt occurs whenever
the processor has failed to respond to an XPR interrupt (ISTA register)
quickly enough, after having initiated a transmission and the message
to be transmitted is not yet complete.
Note:
PCE
When a XMR or an XDU interrupt is generated, it is not possible to send
transparent frames or I frames until the interrupt has been acknowledged
by reading EXIR.
Protocol Error. Used in auto mode only.
A protocol error has been detected in auto mode due to a received
– S or I frame with an incorrect sequence number N (R) or
– S frame containing an I field.
RFO
Receive Frame Overflow
The received data of a frame could not be stored, because the RFIFO is
occupied. The whole message is lost.
This interrupt can be used for statistical purposes and indicates that the
processor does not respond quickly enough to an RPF or RME interrupt (ISTA).
SOV
MOS
Synchronous Transfer Overflow
The synchronous transfer programmed in STCR has not been
acknowledged in time via the SC0/SC1 bit.
MONITOR Status
A change in the MONITOR Status Register (MOSR) has occurred (IOM-2).
A new MONITOR channel byte is stored in MOR0 (IOM-1).
Semiconcuctor Group
126
Register Description
SAW
WOV
Subscriber Awake. Used only if terminal specific functions are
enabled (STCR:TSF = 1).
Indicates that a falling edge on the EAW line has been detected, in case
the terminal specific functions are enabled (TSF-bit in STCR).
Watchdog Timer Overflow. Used only if terminal specific functions
are enabled (STCR:TSF = 1).
Signals the expiration of the watchdog timer, which means that the
processor has failed to set the watchdog timer control bits WTC1 and
WTC2 (ADF1 register) in the correct manner. A reset pulse has been
generated by the ICC-B.
4.1.10
Transmit Address 1
XAD1
Write
Address 24H
7
0
Used in auto mode only.
XAD1 contains a programmable address byte which is appended
automatically to the frame by the ICC-B in auto mode. Depending on
the selected address mode XAD1 is interpreted as follows:
* 2-Byte Address Field
XAD1 is the high byte (SAPI in the ISDN) of the 2-byte address field. Bit
1 is interpreted as the command/response bit “C/R”. It is automatically
generated by the ICC-B following the rules of ISDN LAPD protocol and the
CRI bit value in SAP1 register. Bit 1 has to be set to “0”.
C/R Bit
Command
Response
Transmitting End
subscriber
CRI Bit
0
1
1
0
0
0
network
In the ISDN LAPD the address field extension bit “EA”, i.e. bit 0 of XAD1
has to be set to “0”.
* 1-Byte Address Field
According to the X.25 LAPB protocol, XAD1 is the address of
a command frame.
Note: In standard ISDN applications only 2-byte address fields are used.
Semiconcuctor Group
127
Register Description
4.1.11
Receive Frame Byte Count Low RBCL
Read
Address 25H
Value after reset: 00H
7
0
RBC7 ...
...
...
...
...
...
RBC0
RBC7-0
Receive byte Count
Eight least significant bits of the total number of bytes in a received
message. Bits RBC4-0 indicate the length of a data block currently
available in the RFIFO, the other bits (together with RBCH) indicate
the number of whole 32-byte blocks received.
If exactly 32 bytes are received RBCL holds the value 20H.
4.1.12
Transmit Address 1
XAD2
Write
Address 25H
7
0
Used in auto mode only.
XAD2 contains the second programmable address byte, whose function
depends on the selected address mode:
* 2-Byte Address Field
XAD2 is the low byte (TEI in the ISDN) of the 2-byte address field.
* 1-Byte Address Field
According to the X.25 LAPB protocol, XAD2 is the address of
a response frame.
Note: See note to XAD1 register description.
Semiconcuctor Group
128
Register Description
4.1.13
Received SAPI Register
SAPR
Read
Address 26H
7
0
When a transparent mode 1 is selected SAPR contains the value of the
first address byte of a receive frame.
4.1.14
SAPI1 Register
SAP1
Write
Address 26H
7
0
SAPI1
CRI
0
SAPI1
CRI
SAPI1 value
Value of the first programmable Service Access Point Identifier (SAPI)
according to the ISDN LAPD protocol.
Command/Response Interpretation
CRI defines the end of the ISDN user-network interface the ICC-B is used
on, for the correct identification of “Command” and “Response” frames.
Depending on the value of CRI the C/R-bit will be interpreted by the
ICC-B, when receiving frames in auto mode, as follows:
C/R Bit
CRI Bit
Receiving End
Command
Response
0
1
subscriber
network
1
0
0
1
For transmitting frames in auto mode, the C/R-bit manipulation will also
be done automatically, depending on the value of the CRI-bit
(refer to XAD1 register description).
In message transfer modes with SAPI address recognition the first received
address byte is compared with the programmable values in SAP1, SAP2
and the fixed group SAPI.
In 1-byte address mode, the CRI-bit is to be set to “0”.
Semiconcuctor Group
129
Register Description
4.1.15
Receive Status Register
RSTA
Read
Address 27H
Value after reset: undefined
7
0
RDA RDO CRC RAB SA1
SA0
C/R
TA
RDA
RDO
Receive Data
A “1” indicates that data is available in the RFIFO. After an RME-interrupt,
a “0” in this bit means that data is available in the internal registers RHCR
or SAPR only (e.g. S-frame). See also RHCR-register description table.
Receive Data Overflow
At least one byte of the frame has been lost, because it could not be
stored in RFIFO (1).
CRC
RAB
CRC Check
The CRC is correct (1) or incorrect (0).
Receive Message Aborted
The receive message was aborted by the remote station (1), i.e. a sequence
of 7 1’s was detected before a closing flag.
SA1-0
TA
SAPI Address Identification
TEI Address Identification
SA1-0 are significant in auto-mode and non-auto-mode with a two-byte
address field, as well as in transparent mode 3. TA is significant in all modes
except in transparent modes 2 and 3.
Two programmable SAPI values (SAP1, SAP2) plus a fixed group SAPI
(SAPG of value FC/FEH), and two programmable TEI values (TEI1, TEI2)
plus a fixed group TEI (TEIG of value FFH), are available for address
comparison.
Semiconcuctor Group
130
Register Description
The result of the address comparison is given by SA1-0 and TA, as follows:
Address Match with
st
nd
SA1
SA0
TA
1 Byte
2
Byte
Number of Address
Bytes=1
x
x
x
x
0
1
TEI2
TEI1
-
-
0
0
0
0
1
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
x
SAP2
SAP2
SAPG
SAPG
SAP1
SAP1
TEIG
TEI2
TEIG
TEI1 or TEI2
TEIG
Number of address
Bytes=2
TEI1
reserved
Notes: • If the SAPI values programmed to SAP1 and SAP2 are identical the reception
of a frame with SAP2/TEI2 results in the indication SA1=1, SA0-0, TA=1.
• Normally RSTA should be read by the processor after an RME-interrupt in
order to determine the status of the received frame. The contents of RSTA are
valid only after an RME-interrupt, and remain so until the frame is acknowled-
ged via the RMC-bit.
C/R
Command/Response
The C/R-bit identifies a receive frame as either a command or a response,
according to the LAPD-rules:
Command
Response
Direction
0
1
1
0
Subscriber to network
Network to subscriber
4.1.16
SAP12 Register
SAP2
Write
Address 27H
7
0
S
A
P
I
2
MCS
0
SAP12
SAP12 value
Value of the second programmable Service Access Point Identifier (SAPI)
according to the ISDN LAPD-protocol.
Semiconcuctor Group
131
Register Description
MCS
Modulo Count Select. Used in auto-mode only.
This bit determines the HDLC-control field format as follows:
0: One-byte control field (modulo 8)
1: Two-byte control field (modulo 128)
4.1.17
TEI1 Register 1
TEI1
Write
Address 28H
7
0
T
E
I
1
EA
EA
Address field Extension bit
This bit is set to “1” according to HDLC/LAPD.
In all message transfer modes except in transparent modes 2 and 3,
TEI1 is used by the ICC-B for address recognition. In the case of a two-byte
address field, it contains the value of the first programmable Terminal
Endpoint Identifier according to the ISDN LAPD-protocol.
In the auto-mode with a two-byte address field, numbered frames with the
address SAPI1-TEI1 are handled autonomously by the ICC-B according
to the LAPD-protocol.
Note: If the value FFH is programmed in TEI1, received numbered frames
with address SAPI1-TEI1 (SAPI1-TEIG) are not handled autono-
mously by the ICC-B.
In auto and non-auto-modes with one-byte address field, TEI1 is a command
address, according to X.25 LAPB.
4.1.18
Receive HDLC Control Register
RHCR
Read
Address 29H
7
0
In all modes except transparent modes 2 and 3, this register contains the control field of a re-
ceived HDLC-frame. In transparent modes 2 and 3, the register is not used.
Semiconcuctor Group
132
Register Description
Contents of RHCR
Mode
Modulo 8 (MCS=0) Modulo 128
(MCS=1)
Contents of RFIFO
From 3rd byte after flag
(Note 4)
Auto-mode,
1-byte address
(U/I frames)
Control field
U-frames only:
Control field
(Note 2)
(Note 1)
From 4th byte after flag
(Note 4)
Auto-mode,
2-byte address
(U/I frames)
Control field
U-frames only:
Control field
(Note 2)
(Note 1)
From 4th byte after flag
(Note 4)
Auto-mode,
1-byte address
(I frames)
Control field
compressed form
(Note 3)
From 5th byte after flag
(Note 4)
Auto-mode,
2-byte address
(I frames)
Control field in
compressed form
(Note 3)
2nd byte after flag
3rd byte after flag
From 3rd byte after flag
From 4th byte after flag
Non-auto-mode,
1-byte address
Non-auto-mode,
2-byte address
3rd byte after flag
From 4th byte after flag
From 1st byte after flag
From 2nd byte after flag
Transparent mode 1
Transparent mode 2
Transparent mode 3
–
–
Note 1
S-frames are handled automatically and are not transferred to the micropro-
cessor.
Note 2
Note 3
For U-frames (bit 0 of RHCR = 1) the control field is as in the modulo 8 case.
For I-frames (bit 0 of RHCR = 0) the compressed control field has the same
format as in the modulo 8 case, but only the three LSB’s of the receive and
transmit counters are visible:
bit
7
6
5
4
3
2
1
0
0
N (R)
2-0
P
N (S)
2-0
Note 4
I-field.
Semiconcuctor Group
133
Register Description
4.1.19
TEI2 Register
TEI2
Write
Address 29H
7
0
T
E
I
2
EA
EA
Address field Extension bit
This bit is to be set to “1” according to HDLC/LAPD.
In all message transfer modes except in transparent modes 2 and 3, TEI2 is used by the ICC-B
for address recognition. In the case of a two-byte address field, it contains the value of the sec-
ond programmable Terminal Endpoint Identifier according of the ISDN LAPD-protocol.
In auto and non-auto-modes with one-byte address field, TEI2 is a response address, according
to X.25 LAPD.
4.1.20 Receive Frame Byte Count High
RBCH
Read
Address 30H
Value after reset: 0XXX000002.
7
0
XAC
VN1
VN0
OV
RBC11 RBC10 RBC9 RBC8
XAC
Transmitter Active
The HDLC-transmitter is active when XAC = 1. This bit may be polled.
The XAC-bit is active when
– either an XTF/XIF-command is issued and the frame has not been completely
transmitted
– or the transmission of an S-frame is internally initiated and not yet completed.
Version Number of Chip
VN1-0
OV
0 ... A1 or A3 version
1 ... B1 version
2 ... B2 & B3 version
3 ... Version 2.4
Overflow
A “1” in this bit position indicates a message longer than 4095 bytes.
RBC8-11 Receive Byte Count
Four most significant bits of the total number of bytes in a received message.
Semiconcuctor Group
134
Register Description
Note:
4.1.21
Normally RBCH and RBCL should be read by the processor after an RME-
interrupt in order to determine the number of bytes to be read from the RFIFO,
and the total message length. The contents of the registers are valid only after
an RME-interrupt, and remain so until the frame is acknowledged via the
RMC-bit.
Status Register 2
STAR2
Read
Address 2BH
7
0
0
0
0
0
WFA
0
TREC SDET
SDET
TREC
S-frame detected: this bit is set to “1” by the first received correct I-frame or
S-command with p = 1.
It is reset by reading the STAR2 register.
Timer recovery status:
0: The device is not in the Timer Recovery state.
1: The device is in the Timer Recovery state.
WFA
Waiting for Acknowledge. This bit shows, if the last transmitted I-frame was
acknowledged, i.e. V(A) = V(S) (=> WFA= 0) or was not yet acknowledged,
i.e. V(A)< V(S) (=> WFA = 1).
4.2 Special Purpose Registers: IOM-1Mode
The following register description is only valid if IOM-1 Mode is selected (ADF2:IMS = 0).
For IOM-2 Mode refer to chapter 4.3.
4.2.1
Serial Port Control Register
SPCR
Read/Write
Address 30H
Value after reset: 00H
7
0
SPU
SAC
SPM
TLP
C1C1
C1C0
C2C1
C2C0
Important Note
After a hardware reset the pins SDAX/SDS1 and SCA/FSD/SDS2 are
both “low” and have the functions of SDS1 and SDS2 in terminal timing
mode (since SPM = 0), respectively, until the SPCR is written to for the
first time. From that moment, the function taken on by these pins
depends on the state of the IOM Mode Select bit IMS (ADF2 register).
Semiconcuctor Group
135
Register Description
SPU
Software Power Up. Used in TE-mode only.
Setting this bit to 1 will pull the IDP1-line low. This will enforce the connected
layer-1 device to deliver IOM-clocking.
After power down in TE-mode the SPU-bit has to be set to “1” and then cleared
again.
After a subsequent CIC-interrupt (C/I-code change; ISTA) and reception of the
C/I-code “PU” (Power Up indication in TE-mode) the reaction of the processor
would be:
– to write an Activate Request command as C/I-code in the CIXR-register
– to reset the SPU-bit and wait for the following CIC-interrupt.
SAC
SPM
SIP-port activation; SIP-port is in high impedance state (SAC=0) or operating
(SAC=1).
Serial Port Timing Mode; Depending on the interface mode, the following timing
options are provided.
0 Timing mode 0; SIP (SLD) operates in master mode, SCA-supplies the 128-kHz
data clock signal for port A (SSI).
Typical applications: TE, NT-modes
1 Timing mode 1; SIP (SLD) operates in slave mode, FSD supplies a delayed
frame synchronization signal for the IOM interface, serial port A (SSI) is not
used.
Typical applications: LT-T, LT-S-modes.
TLP
Test Loop
When set to 1 the IDP1 and IDP0 lines are internally connected together, and the
times T1 and T2 are reduced (cf. TIMR).
C1C1, C1C0
Channel 1 Connect
Switching of B1 channel
C1R
B1CR
Read
C1C1
C1C0
Read
Write
Application(s)
0
0
1
1
0
1
0
1
SIP
SIP
SDAR
IOM
SIP
–
–
IOM
IOM
IOM
–
B1 not switched, SIP-looping
B1 switched to/from SIP
B1 switched to/from SPa (SSI)
IOM-looping
IOM
Semiconcuctor Group
136
Register Description
C2C1, C2C0
Channel 2 Connect
Switching of B2-channel
C2R
B2CR
Read
C2C1
C2C0
Read
Write
Application(s)
0
0
1
1
0
1
0
1
SIP
SIP
SDAR
IOM
SIP
–
–
IOM
IOM
IOM
–
B2 not switched, SIP-looping
B2 switched to/from SIP
B2 switched to/from SPa (SSI)
IOM-looping
IOM
4.2.2
Command/Indication Receive Register
CIRR
Read
Address 31H
Value after reset: 7CH.
7
0
0
BAS
C
O
D
R
CIC0
0
BAS
Bus Access Status
Indicates the state of the TIC-bus:
0: the ICC-B itself occupies the D-and C/I-channel
1: another device occupies the D-and C/I-channel
CODR
CIC0
C/I-code Receive
Value of the receive Command/Indication code. A C/I-code is loaded in CODR
only after being the same in two consecutive IOM-frames and the previous
code has been read from CIRR.
C/I-Code Change
A change in the received Command/Indication code has been recognized.
This bit is set only when a new code is detected in two consecutive IOM-
frames. It is reset by a read of CIRR.
Note:
The BAS and CODR bits are updated every time a new C/I-code is detected
in two consecutive IOM-frames.
If several consecutive codes are detected and CIRR is not read, only the first
and the last C/I-code (and BAS bit) is made available in CIRR at the first and
second read of that register, respectively.
Semiconcuctor Group
137
Register Description
4.2.3
Command/Indication Transmit Register
CIXR
Write
Address 31H
Value after reset: 3CH.
7
0
RSS
BAC
C
O
D
X
TCX
ECX
RSS
Reset Source Select
Only valid if the terminal specific functions are activated (STCR:TSF).
0 → Subscriber or Exchange Awake
As reset source serves:
– a falling edge on the EAW-line (External Subscriber Awake)
– a C/I-code change (Exchange Awake).
A logical zero on the EAW-line activates also the IOM-interface clock
and frame signal, just as the SPU-bit (SPCR) does.
1 → Watchdog Timer
The expiration of the watchdog timer generates a reset pulse.
The watchdog timer will be reset and restarted, when two specific bit
combinations are written in the ADF1-register within the time period of
128 ms (see also ADF1 register description).
After a reset pulse generated by the ICC-B and the corresponding
interrupt (WOV, SAW or CIC) the actual reset source can be read from
the ISTA and EXIR-register.
BAC
Bus Access Control
Only valid if the TIC-bus feature is enabled (MODE:DIM2-0).
If this bit is set, the ICC-B will try to access the TIC-bus to occupy the
C/I-channel even if no D-channel frame has to be transmitted. It should be reset
when the access has been completed to grant a similar access to other devices
transmitting in that IOM-channel.
Note: Access is always granted by default to the ICC-B with TIC-bus Address
(TBA2-0, STCR register) “7”, which is the lowest priority in a bus configuration.
CODX C/I-Code Transmit
Code to be transmitted in the C/I-channel.
T-channel transmit
TCX
ECX
Output on IOM in T-channel.
E-channel transmit
Output on IOM in E-channel.
Semiconcuctor Group
138
Register Description
4.2.4
4.2.5
4.2.6
MONITOR Receive Register
MOR
Read
Address 32H
7
0
Contains the MONITOR data received according to the MONITOR chan-
nel protocol (E-bit = 0).
MONITOR Transmit Register
MOX
Write
Address 32H
7
0
The byte written into MOX is transmitted once in the MONITOR
channel.
SIP Signaling Code Receive
SSCR
Read
Address 33H
7
0
SSCR SIP-signaling code received; only valid in timing mode 0 (SPCR:SPM = 0).
The signaling byte received on SIP can be read from this register.
4.2.7
SIP Signaling Code Transmit
SSCX
Write
Address 33H
Value after reset: FFH
7
0
Semiconcuctor Group
139
Register Description
SSCX SIP signaling code transmit; significant only in timing mode 0 (SPCR:SPM = 0).
The contents of SSCX are continuously output in the signaling byte on SIP (SLD).
4.2.8
SIP Feature Control Read
SFCR
Read
Address 34H
7
0
Contains the FC-data received on SIP (timing mode 0 only,
SPCR:SPM = 0).
4.2.9
SIP Feature Control Write
SFCW
Write
Address 34H
7
0
The byte written into SFCW is output once on SIP in the FC-channel
(timing mode 0 only, SPCR:SPM = 0).
4.2.10 Channel Register 1
C1R
Read/Write
Address 35H
7
0
Contains the value received/transmitted in the B1-channel
(cf. C1C1, C1C0, SPCR-register).
4.2.11 Channel Register 2
C2R
Read/Write
Address 36H
7
0
Contains the value received/transmitted in the B2-channel
(cf. C2C1, C2C0, SPCR-register).
Semiconcuctor Group
140
Register Description
4.2.12 B1 Channel Register
B1CR
Read
Address 37H
7
0
Contains the value received in the B1-channel, as if programmed
(cf. C1C1, C1C0, SPCR-register).
4.2.13 Synchronous Transfer Control Register
STCR
Write
Address 37H
Value after reset: 00H
7
0
TSF
TBA2
TBA1 TBA0
ST1
ST0
SC1
SC0
TSF
Terminal Specific Functions
0
1
No terminal specific functions
The terminal specific functions are activated, such as
– Watchdog Timer
– Subscriber/Exchange Awake (SIP/EAW).
In this case the SIP/EAW-line is always an input signal which can serve
as a request signal from the subscriber to initiate the awake function in
a terminal.
A falling edge on the EAW-line generates an SAW interrupt (EXIR).
When the RSS-bit in the CIXR-register is zero, a falling edge on the
EAW-line (Subscriber Awake) or a C/I-code change (Exchange Awake)
initiates a reset pulse.
When the RSS-bit is set to one a reset pulse is triggered only by the
expiration of the watchdog timer (see also CIXR-register description).
Note:
The TSF-bit will be cleared only by hardware reset.
TBA2-0 TIC Bus Address
Defines the individual address for the ICC-B on the IOM-bus.
This address is used to access the C/I and D-channel on the IOM.
Note:
One device liable to transmit in C/I and D-fields on IOM should always be given
the address value “7”.
Semiconcuctor Group
141
Register Description
ST1
ST0
SC1
Synchronous Transfer 1
When set, causes the ICC-B to generate an SIN-interrupt status (ISTA register)
at the beginning of an IOM-frame.
Synchronous Transfer 0
When set, causes the ICC-B to generate an SIN-interrupt status (ISTA register)
at the middle of an IOM-frame.
Synchronous Transfer 1 Completed
After an SIN-interrupt the processor has to acknowledge the interrupt by
setting the SC1-bit before the middle of the IOM-frame, if the interrupt was
originated from a Synchronous Transfer 1 (ST1).
Otherwise an SOV-interrupt (EXIR register) will be generated.
Synchronous Transfer 0 Completed
SC0
After an SIN-interrupt the processor has to acknowledge the interrupt by
setting the SC0-bit before the start of the next IOM-frame, if the interrupt was
originated from a Synchronous Transfer 0 (ST0).
Otherwise an SOV-interrupt (EXIR register) will be generated.
Note:
ST0/1 and SC0/1 are useful for synchronizing MP-accesses and receive/
transmit operations.
4.2.14 B2 Channel Register
B2CR
Read
Address 38H
7
0
Contains the value received in the B2-channel, as if programmed
(cf. C2C1, C2C0, SPCR-register).
4.2.15 Additional Feature Register 1
ADF1
Write
Address 38H
Value after reset: 00H
7
0
WTC1 WTC2
0
0
0
0
0
ITF
Semiconcuctor Group
142
Register Description
WTC1, WTC2 Watchdog Timer Control 1, 2
After the watchdog timer mode has been selected (STCR:TSF = CIXR:RSS = 1)
the watchdog timer is started.
During every time period of 128 ms the processor has to program the WTC1- and
WTC2-bit in the following sequence:
WTC1
WTC2
1.
2.
1
0
0
1
to reset and restart the watchdog timer.
If not, timer expires and a WOV-interrupt (EXIR) together with a reset pulse is
generated.
ITF
Inter-frame Time Fill
Selects the inter-frame time fill signal which is transmitted between HDLC-frames.
0: idle (continuous 1 s),
1: flags (sequence of patterns: “0111 1110”)
Note:
In TE- and LT-T-applications with D-channel access handling (collision
resolution), the only possible inter-frame time fill signal is idle (continuous 1s).
Otherwise the D-channel on the S/T-bus cannot be accessed.
4.2.16 Additional Feature Register 2
ADF2
Read/Write
Address 39H
Value after reset: 00H
7
0
IMS
0
0
0
0
0
0
0
IMS
IOM-mode selection
IOM-1 interface mode is selected when IMS = 0.
Semiconcuctor Group
143
Register Description
4.3 Special Purpose Registers: IOM-2 Mode
The following register description is only valid if IOM-2 is selected (ADF2:IMS-1).
For IOM-1 mode refer to chapter 4.2.
4.3.1
Serial Port Control Register
SPCR
Read/Write
Address 30H
Value after reset: 00H
7
0
SPU
0
SPM
TLP
C1C1
C1C0
C2C1 C2C0
Important Note: After a hardware reset the pins SDAX/SDS1 and SCA/FSD/SDS2 are
both “low” and have the functions of SDS1 and SDS2 in terminal
timing mode (since SPM = 0), respectively, until the SPCR is written
to for the first time. From that moment, the function taken on by
these pins depends on the state of the IOM Mode Select bit IMS
(ADF2 register).
SPU
Software Power UP. Used in TE-mode only.
Setting this bit to 1 and ADF1:IDC to 1 will pull the IDP1-line to low. This will
enforce connected layer 1 devices to deliver IOM-clocking.
After power down in TE-mode the SPU-bit and the ADF1:IDC bit have to be
set to “1” and then cleared again.
After a subsequent CIC-interrupt (C/I-code change; ISTA) and reception of the
C/I-code “PU” (Power Up indication in TE-mode) the reaction of the processor
would be:
– to write an Activate Request command as C/I-code in the CIX0-register.
– to reset the SPU and SQXR:IDC bits and wait for the following CIC-interrupt.
Serial Port Timing Mode
SPM
TLP
0 Terminal mode; all three channels of the IOM-2 interface are used
application: TE-mode
1 Non-terminal mode; the programmed IOM-channel (ADF1:CSEL2-0) is used
applications: LT-T, LT-S modes (8 channels structure IOM-2)
Test Loop
When set to 1 the IDP1 and IDP0-lines are internally connected together, and
the times T1 and T2 are reduced (cf. TIMR).
Semiconcuctor Group
144
Register Description
C1C1, C1C0 Channel 1 Connect
Determines which of the two channels B1 or IC1 is connected to register
C1R and/or B1CR, for monitoring, test-looping and switching data to/from
the processor.
C1R
Read
IC1
B1CR
Read
B1
C1C1
C1C0
Write
Application(s)
0
0
–
B1-monitoring + IC1-monitoring
0
1
1
1
0
1
IC1
–
IC1
B1
B1
B1
B1
–
B1-monitoring + IC1-looping
from/to IOM
B1-access from/to S0; transmission of a
constant value in B1-channel to S0.
B1
B1-looping from S0; transmission of a
variable pattern in B1-channel to S0.
C2C1, C2C0 Channel 2 Connect
Determines which of the two channels B2 or IC2 is connected to register
C2R and/or B2CR, for monitoring, test-looping and switching data
to/from the processor.
C2R
Read
IC2
B2CR
Read
B2
C2C1
C2C0
Write
Application(s)
0
0
–
B2-monitoring + IC2-monitoring
0
1
1
1
0
1
IC2
–
IC2
B2
B2
B2
B2
–
B2-monitoring + IC2-looping
from/to IOM
B2-access from/to S0; transmission of a
constant value in B2-channel to S0.
B2
B2-looping from S0; transmission of a
variable pattern in B2-channel to S0.
Note: B-channel access is only possible in TE-mode.
Semiconcuctor Group
145
Register Description
4.3.2
Command/Indication Receive 0
CIR0
Read
Address 31H
Value after reset: 7CH
7
0
0
BAS
C
O
D
R
0 CIC0
CIC1
BAS
Bus Access Status
Indicates the state of the TIC-bus:
0: the ICC-B itself occupies the D- and C/I-channel
1: another device occupies the D- and C/I-channel
CODR0
CIC0
C/I code 0 Receive
Value of the received Command/Indication code. A C/I-code is loaded in
CODR0 only after being the same in two consecutive IOM-frames and the
previous code has been read from CIR0.
C/I Code 0 Change
A change in the received Command/Indication code has been recognized.
This bit is set only when a new code is detected in two consecutive
IOM-frames. It is reset by a read of CIR0.
CIC1
C/I Code 1 Change
A change in the received Command/Indication code in IOM-channel 1 has
been recognized. This bit is set when a new code is detected in one
IOM-frame. It is reset by a read of CIR0.
CIC1 is only used if Terminal Mode is selected.
Note:
The BAS and CODR0 bits are update every time a new C/I-code is detected
in two consecutive IOM-frames.
If several consecutive valid new codes are detected and CIR0 is not read,
only the first and the last C/I code (and BAS bit) is made available in CIR0
at the first and second read of that register, respectively.
4.3.3
Command/Indication Transmit 0
CIX0
Write
Address 31H
Value after reset: 3FH
7
0
RSS
BAC
C
O
D
X
0 1
1
Semiconcuctor Group
146
Register Description
RSS
Reset Source Select
Only valid if the terminal specific functions are activated (STCR:TSF).
0 → Subscriber or Exchange Awake
As reset source serves:
– a falling edge on the EAW-line (External Subscriber Awake)
– a C/I code change (Exchange Awake).
A logical zero on the EAW-line activates also the IOM-interface clock
and frame signal, just as the SPU-bit (SPCR) does.
1 → Watchdog Timer
The expiration of the watchdog timer generates a reset pulse.
The watchdog timer will be reset and restarted, when two specific bit
combinations are written in the ADF1-register within the time period of
128 ms (see also ADF1 register description).
After a reset pulse generated by the ICC-B and the corresponding inter-
rupt (WOV, SAW or CIC) the actual reset source can be read from the
ISTA and EXIR-register.
BAC
Bus Access Control
Only valid if the TIC-bus feature is enabled (MODE:DIM2-0).
If this bit is set, the ICC-B will try to access the TIC-bus to occupy the
C/I-channel even if no D-channel frame has to be transmitted. It should be
reset when the access has been completed to grant a similar access to other
devices transmitting in that IOM-channel.
Note: Access is always granted by default to the ICC-B with TIC-Bus Address
(TBA2-0, STCR register) “7”, which has the lowest priority in a bus
configuration.
CODX0
4.3.4
C/I-Code 0 Transmit
Code to be transmitted in the C/I-channel / C/I-channel 0.
MONITOR Receive Channel 0
MOR0
Read
Address 32H
7
0
Contains the MONITOR data received in IOM-MONITOR Channel/
MONITOR channel 0 according to the MONITOR channel protocol.
Semiconcuctor Group
147
Register Description
4.3.5
MONITOR Transmit Channel 0
MOX0
Write
Address 32H
7
0
Contains the MONITOR data transmitted in IOM-MONITOR Channel/
MONITOR channel 0 according to the MONITOR channel protocol.
4.3.6
Command/Indication Receive 1
CIR1
Read
Address 33H
7
0
C
O
D
R
1
MR1
MX1
CODR1
MR1
C/I-Code 1 Receive; only valid in terminal mode (SPCR:SPM = 0)
Bits 7-2 of C/I-channel 1
MR Bit
Bit 1 of C/I-channel 1
MX Bit
MX1
Bit 0 of C/I/channel 1
4.3.7
Command/Indication Transmit 1
CIX1
Write
Address 33H
Value after reset: FFH
7
0
C
O
D
X
1
1
1
CODX1
C/I-Code 1 Transmit; significant only in terminal mode (SPCR:SPM = 0).
Bits 7-2 of C/I-channel 1
Semiconcuctor Group
148
Register Description
4.3.8
MONITOR Receive Channel 1
MOR1
Read
Address 34H
7
0
Used only in terminal mode (SPCR:SPM = 0).
Contains the MONITOR data received in IOM-channel 1 according to the
MONITOR channel protocol.
MONITOR Transmit Channel 1MOX1WriteAddress 34H
7
0
Used only in terminal mode (SPCR:SPM = 0).
Contains the MONITOR data to be transmitted in IOM-channel 1 according to
the MONITOR channel protocol.
4.3.9
Channel Register 1
C1R
Read/Write
Address 35H
7
0
Used only in terminal mode (SPCR:SPM = 0).
Contains the value received/transmitted in IOM-channel B1 or IC1, as the case
may be (cf. C1C1, C1C0, SPCR-register).
4.3.11 Channel Register 2
C2R
Read/Write
Address 36H
7
0
Used only in terminal mode (SPCR:SPM = 0).
Contains the value received/transmitted in IOM-channel B2 or IC2, as the case
may be (cf. C2C1, C2C0, SPCR-register).
Semiconcuctor Group
149
Register Description
4.3.12 B1 Channel Register
B1CR
Read
Address 37H
7
0
Used only in terminal mode (SPCR:SPM = 0).
Contains the value received in IOM-channel B1, if programmed
(cf. C1C1, C1C0, SPCR-register).
4.3.13 Synchronous Transfer Control Register STCR Write
Address 37H
Value after reset: 00H
7
0
TSF
TBA2
TBA1 TBA0
ST1
ST0
SC1
SC0
TSF
Terminal Specific Functions
0 → No terminal specific functions
1 → The terminal specific functions are activated, such as
– Watchdog Timer
– Subscriber/Exchange Awake (SIP/EAW).
In this case the SIP/EAW-line is always an input signal which can serve
as a request signal from the subscriber to initiate the awake function in
a terminal.
A falling edge on the EAW-line generates an SAW-interrupt (EXIR).
When the RSS-bit in the CIX0-register is zero, a falling edge on the
EAW-line (Subscriber Awake) or a C/I-code change (Exchange Awake)
initiates a reset pulse.
When the RSS-bit is set to one a reset pulse is triggered only by the
expiration of the watchdog timer (see also CIX0-register description).
Note:
The TSF-bit will be cleared only by a hardware reset.
Semiconcuctor Group
150
Register Description
TBA2-0
TIC Bus Address
Defines the individual address for the ICC-B on the IOM-bus.
This address is used to access the C/I- and D-channel on the IOM.
Note:
ST1
One device liable to transmit in C/I- and D-fields on the IOM should always
be given the address value “7”.
Synchronous Transfer 1
When set, causes the ISAC-S to generate an SIN-interrupt status (ISTA-
register) at the beginning of an IOM-frame.
ST0
Synchronous Transfer 0
When set, causes the ICC-B to generate an SIN-interrupt status (ISTA-
register) at the middle of an IOM-frame.
SC1
Synchronous Transfer 1 Completed
After an SIN-interrupt the processor has to acknowledge the interrupt by
setting the SC1-bit before the middle of the IOM-frame, if the interrupt was
originated from a Synchronous Transfer 1 (ST1).
Otherwise an SOV-interrupt (EXIR-register) will be generated.
SC0
Synchronous Transfer 0 Completed
After an SIN-interrupt the processor has to acknowledge the interrupt by
setting the SC0-bit before the start of the next IOM-frame, if the interrupt was
originated from a Synchronous Transfer 0 (ST0).
Otherwise an SOV-interrupt (EXIR-register) will be generated.
Note:
ST0/1 and SC0/1 are useful for synchronizing MP-accesses and receive/
transmit operations.
4.3.14 B2 Channel Register
B2CR
Read
Address 38H
7
0
Used only in terminal mode (SPCR:SPM = 0).
Contains the value received in the IOM-channel B2, if programmed (cf. C2C1,
C2C0, SPCR-register).
Semiconcuctor Group
151
Register Description
4.3.15 Additional Feature Register 1
ADF1
Write
Address 38H
Value after reset: 00H
7
0
WTC1 WTC2 CI1E
IDC
CSEL2 CSEL1 CSEL0 ITF
WTC1, WTC2 Watchdog Timer Control 1, 2
After the watchdog timer mode has been selected (STCR:TSF = CIX0:RSS = 1)
the watchdog timer is started.
During every time period of 128 ms the processor has to program the WTC1-
and WTC2-bit in the following sequence:
WTC1
WTC2
1.
2.
1
0
0
1
to reset and restart the watchdog timer.
If not, the timer expires and a WOV-interrupt (EXIR) together with a reset
pulse is generated.
CI1E
IDC
C/I-channel 1 interrupt enable
Interrupt generation of CIR0:CIC1 is enabled (1) or masked (0).
IOM-direction control
Terminal mode (SPCR:SPM = 0)
0 ... Master mode
Layer-2 transmits IOM-channel 0 and 2 on IDP1, channel 1 on IDP0.
1 ... Slave mode
Layer-2 transmits IOM-channel 0, 1 and 2 on IDP1.
Non-Terminal mode (SPCR:SPM = 1)
0 ... normal mode
MONITOR, D- and C/I-channels are transmitted on IDP1 from layer-2 to
layer-1
1 ... reversed mode
MONITOR, D- and C/I-channels are transmitted on IDP0 from layer-2 to
the system.
Semiconcuctor Group
152
Register Description
CSEL2-0 Channel Select. Used in non-terminal mode (SPCR:SPM = 1).
Select one IOM-channel out of 8, where the ICC-B is to receive/transmit.
“000” channel 0 (first channel in IOM-frame)
“001” channel 1
...
“111” channel 7 (last channel in IOM-frame)
Inter-Frame Time Fill
ITF
Selects the inter-frame time fill signal which is transmitted between
HDLC-frames.
0: idle (continuous 1 s),
1: flags (sequence of patterns: “0111 1110”)
Note: In TE- and LT-T-applications with D-channel access handling
(collision resolution), the only possible inter-frame time fill signal is
idle (continuous 1s). Otherwise the D-channel on the S/T-bus
cannot be accessed.
4.3.16 Additional Feature Register 2
ADF2
Read/Write
Address 39H
Value after reset: 00H
7
0
IMS
D2C2
D2C1 D2C0
ODS
D1C2
D1C1 D1C0
Semiconcuctor Group
153
Register Description
IMS
IOM-mode selection
IOM-2 interface mode is selected when IMS = 1.
Data strobe control; used in IOM-2 mode only.
D2C2-0
D1C2-0
These bits determine the polarity of the two independent strobe signals SDS1
and SDS2 as follows:
DxC2
DxC1
DxC0
SDSx
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
always low
high during B1
high during B2
high during B1 + B2
always low
high during IC1
high during IC2
high during IC1 + IC2
The strobe signals allow standard combos or data devices to access a
programmable channel.
Note: In non-terminal mode (SPCR:SPM = 1) IC1, IC2 correspond to B1,
B2 channels of the IOM-channel as programmed to ADF1:CSEL
2 - 0 + 1.
ODS
Output driver selection;
Tristate drivers (1) or open drain drivers (0) are used for the IOM-interface.
4.3.17 MONITOR Status Register
MOSR
Read
Address 3AH
Value after reset: 00H
7
0
MDR1 MER1 MDA1 MAB1 MDR0 MER0 MDA0 MAB0
Semiconcuctor Group
154
Register Description
MDR1
MER1
MDA1
MONITOR channel 1 Data Received
MONITOR channel 1 End of Reception
MONITOR channel 1 Data Acknowledged
The remote end has acknowledged the MONITOR byte being transmitted.
MONITOR channel 1 Data Abort
MAB1
MDR0
MER0
MDA0
MONITOR channel 0 Data Received
MONITOR channel 0 End of Reception
MONITOR channel 0 Data Acknowledged
The remote end has acknowledged the MONITOR byte being transmitted.
MONITOR channel 0 Data Abort
MAB0
4.3.18 MONITOR Control Register
MOCR
Write
Address 3AH
Value after reset: 00H
7
0
MRE1 MRC1 MIE1
MXC1 MRE0 MRC0 MIE0
MXC0
MRC1,0
MR Bit Control (IOM-channel 1,0)
Determines the value of the MR-bit:
0.. MR always “1”. In addition, the MDR1/MDR0 interrupt is blocked, except for
the first byte of a packet (if MRE 1/0=1).
1.. MR internally controlled by the ICC-B according to MONITOR channel
protocol. In addition, the MDR1/MDR0-interrupt is enabled for all received bytes
according to the MONITOR channel protocol (if MRE1,0=1).
MXC1,0
MX Bit Control (IOM-channel 1,0)
Determines the value of the MX-bit:
0.. MX always “1”.
1.. MX internally controlled by the ICC-B according to MONITOR channel
protocol.
MIE1,0
MONITOR transmit interrupt enable (IOM-channel 1,0)
MONITOR interrupt status MER1/0, MDA1/0, MAB1/0 generation is
enabled (1) or masked (0).
MRE1,0
MONITOR receive interrupt enable (IOM-channel 1,0)
MONITOR interrupt status MDR1/MDR0 generation is enabled (1) or
masked (0).
Semiconcuctor Group
155
Electrical Characteristics
5
Electrical Characteristics
Absolute Maximum Ratings
Parameter
Symbol Limit Values
Unit
Voltage on any pin with respect to ground
V
S
– 0.4 to V DD + 0.4
V
o C
o C
Ambient temperature under bias
PEB 2070
PEF 2070
T
T
A
A
0 to 70
- 40 to 85
o C
Storage temperature
T
stg
– 65 to 125
Note: Stresses above those listed here may cause permanent damage to the device.
Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
DC Characteristics
PEB 2070: T
PEF 2070: T
A
A
= 0 to 70 oC, V DD = 5 V, V SS = 0 V.
= - 40 to 85oC, V DD = 5 V, V SS = 0 V.
Limit Values
Parameter
Symbol
Unit Test Condition
min.
max.
L-input voltage
H-input voltage
V
V
IL
– 0.4
2.0
0.8
V
V
IH
V
DD
+ 0.4
L-output voltage
V
OL
0.45
V
I
I
OL =7 mA pin IDP0, IDP1
OL = 2 mA all other pins
H-output voltage
H-output voltage
V
V
OH
OH
2.4
V
V
I
I
OH =– 400 µA
OH =– 100 µA
V
DD
– 0.5
DLC: 512 kHz V DD = 5 V
DLC: 1536 kHz inputs at
DLC: 4096 kHz 0 V/V DD
no output
Power operational
supply
current
I
CC
1.6
3.5
8.0
mA
mA
mA
loads
power down
0.6
10
mA
Input leakage current
Output leakage current
I
I
LI
LO
µA
0 V < V IN, V DD to 0 V
0 V < V OUT < V DD to 0 V
Semiconductor Group
156
Electrical Characteristics
Capacitances
= 25oC, V DD = 5 V ± 5 %, V SS = 0 V, f
T
A
C
= 1 MHz, unmeasured pins returned to GND.
Parameter
Symbol
Limit Values
Unit
typ.
5
max.
10
Input capacitance
Output capacitance
C
C
IN
pF
pF
OUT
8
15
f
C
= 1 MHz
I/O capacitance
= 1 MHz
C
IO
10
20
pF
f
C
AC Characteristics
PEB 2070: T
PEF 2070: T
A
A
= 0 to 70 oC, V DD = 5 V ± 5%
= - 40 to 85 oC, V DD = 5 V ± 5%
Inputs are driven to 2.4 V for logical “1” and to 0.4 V for a logical “0”. Timing measurements
are made at 2.0 V for a logical “1” and 0.8 V for a logical “0”. The AC testing input/output
waveforms are shown below.
2.4
2.0
0.8
2.0
0.8
Device
Under
Test
Test Points
C Load = 150 pF
0.45
ITS00621
Figure 34
Input/Output Waveform and Load Circuit for AC Tests
Semiconductor Group
157
Electrical Characteristics
Microprocessor Interface Timing
Siemens/Intel Bus Mode
t RR
t RI
RD x CS
t DF
t RD
Data
AD0 - AD7
ITT00712
Figure 35
µP Write Cycle
t WW
t WI
WR x CS
AD0 -AD7
t WD
t DW
Data
ITT00713
Figure 36
µP Write Cycle
Semiconductor Group
158
Electrical Characteristics
t AA
tAD
ALE
WR x CS or
RD x CS
t ALS
t AL
t LA
AD0 - AD7
Address
ITT00714
Figure 37
Multiplexed Address Timing
WR x CS or
RD x CS
t AS
t AH
A0 - A5
Address
ITT00715
Figure 38
Non-Multiplexed Address Timing
Semiconductor Group
159
Electrical Characteristics
Motorola Bus Mode
R/W
t DSD
tRWD
t RI
t RR
CS x DS
D0 - D7
t DF
t RD
Data
ITT00716
Figure 39
µP Read Cycle
R/W
t DSD
t RWD
t WW
t WI
CS x DS
t WD
t DW
AD0 - AD7
Data
ITT00717
Figure 40
µP Write Cycle
CS x DS
t AS
t AH
AD0 - AD5
ITT00718
Figure 41
Address Timing
Semiconductor Group
160
Electrical Characteristics
Parameter and Values of the Bus Modes
Parameter
Symbol
Limit Values
max.
Unit
min.
30
20
10
0
ALE pulse width
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
AA
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Address setup time to ALE
Address hold time from ALE
Address latch setup time to WR, RD
Address setup time to WR, RD
Address hold time from WR, RD
ALE pulse delay
AL
LA
ALS
AS
35
20
15
0
AH
AD
DSD
RR
RD
DF
DS delay after R/W setup
RD pulse width
110
Data output delay from RD
Data float from RD
110
25
RD control interval
RI
70
60
25
10
70
WR pulse width
WW
DW
WD
WI
Data setup time to WR x CS
Data hold time from WR x CS
WR control interval
Semiconductor Group
161
Electrical Characteristics
Serial Interface Timing
IOM® Timing
DCL
FSC
tFSS
tFSH
tFSW
tFDD
FSD
tIIH
tIIS
IDPO/1(I)
IOM R -1 Mode
1st Bit
tIIH
tIIS
IDPO/1(I)
IOM R -2 Mode
1st Bit
tIOD
IDPO/1(O)
SDS1/ 2
1st Bit
tIOF
tSDF
tSDD
ITT00719
Figure 42
IOM® Timing
Semiconductor Group
162
Electrical Characteristics
IOM® Mode
Parameters and Values of IOM Mode
Limit Values
Parameter
Symbol
Unit Test Condition
min.
max.
IOM output data delay
IOM input data setup
t
t
IOD
IIS
20
20
140
100
ns
ns
IOM-1
IOM-2
40
20
IOM-1
IOM-2
IOM input data hold
IOM output from FSC
Strobe signal delay
Strobe delay from FSC
Frame sync setup
Frame sync hold
Frame sync width
FSD delay
t
t
t
t
t
t
t
t
IIH
20
ns
ns
ns
ns
ns
ns
ns
ns
IOF
80
See note
See note
SDD
SDF
FSS
FSH
FSW
FDD
120
120
50
30
40
20
140
Note: This delay is applicable in two cases only:
1) When FSC appears for the first time, e.g. at system power-up
2) When FSC appears before the excepted start of a frame
Semiconductor Group
163
Electrical Characteristics
HDLC Mode
DCL (I)
FSC (I)
tFH1
t FS1
t FH1
t ODZ
t ODD
t ODZ
High Impedance
High Impedance
SDBX
SDBR
t IDH
t IDS
ITT00720
Figure 43
FSC (Strobe) Characteristics
Parameter
Symbol
Limit Values
max.
Unit
min.
100
30
FSC set-up time
FSC hold time
t
t
t
FS1
FH1
OZD
t
CPH + 70
ns
ns
ns
Output data from high impedance
to active
80
Output data from active to
high impedance
t
ODZ
40
ns
Output data delay from DCL
Input data setup
t
t
t
ODD
IDS
20
10
30
100
ns
ns
ns
Input data hold
IDH
Semiconductor Group
164
Electrical Characteristics
Serial Port A (SSI) Timing
B1Channel
B2 Channel
tFSW
FSC
DCL
tFSH
tFSS
tSCD
tSCD
SCA
tSSS
tSSH
SDAR
SDAX
tSSD
ITT00721
Figure 44
SSI Timing
Parameter
Symbol
Limit Values
max.
Unit
min.
20
SCA clock delay
SSI data delay
SSI data setup
SSI data hold
t
t
t
t
t
t
t
SCD
SSD
SSS
SSH
FSS
FSH
FSW
140
140
ns
ns
ns
ns
ns
ns
ns
20
40
20
Frame sync setup
Frame sync hold
Frame sync width
50
30
40
Semiconductor Group
165
Electrical Characteristics
SLD Timing
FSC
tFSW
tFSS
tFSH
DCL
tSLD
tSLD
tSLD
SIP(I/O)
Last Bit OUT
First Bit IN
ITT00722
Figure 45
SLD Timing
Parameter
Symbol
Limit Values
max.
Unit
min.
20
SLD data delay
SLD data setup
SLD data hold
t
t
t
t
t
t
SLD
SLS
SLH
FSS
FSH
FSW
140
ns
ns
ns
ns
ns
ns
30
30
Frame sync setup
Frame sync hold
Frame sync width
50
30
40
Semiconductor Group
166
Electrical Characteristics
Clock Timing
3.5 V
0.8 V
t WH
t WL
ITT00723
t P
Figure 46
Definition of Clock Period and Width
Limit Values
Parameter
Symbol
Unit Test Condition
min.
max.
Clock period
t
t
t
t
t
t
P
1000
200
200
240
100
100
ns
ns
ns
ns
ns
ns
IOM-1
IOM-1
IOM-1
IOM-2
IOM-2
IOM-2
Clock width high
Clock width low
Clock period
WH
WL
P
Clock width high
Clock width low
WH
WL
Reset
t RES
RES
ITT00724
Figure 47
Reset Signal Characteristics
Parameter
Symbol
Limit Values
min.
Test Condition
Length of active
high state
t
RES
2 x DCL
clock
During power up
cycles
Semiconductor Group
167
Package Outlines
6
Package Outlines
Plastic Package, P-DIP-24
(Plastic Dual-In-Line Package)
Plastic Package, P-LCC-28-R (SMD)
(Plastic-Leaded Chip Carrier)
Sorts of Packing
Package outlines for tubes, trays etc. are contained in our
Data Book “Package Information”
Dimensions in mm
SMD = Surface Mounted Device
Semiconductor Group
168
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