LXT914 [INTEL]

Intel® LXT914 Flexible Quad Ethernet Repeater; 英特尔® LXT914灵活四路以太网中继器
LXT914
型号: LXT914
厂家: INTEL    INTEL
描述:

Intel® LXT914 Flexible Quad Ethernet Repeater
英特尔® LXT914灵活四路以太网中继器

中继器 以太网
文件: 总45页 (文件大小:959K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
Intel® LXT914 Flexible Quad Ethernet  
Repeater  
Datasheet  
The Intel® LXT914 Flexible Quad Ethernet Repeater (called hereafter the LXT914 Repeater) is  
an integrated multi-port repeater designed for mixed-media networks. It provides all the active  
circuitry required for the repeater function in a single CMOS device. It includes one Attachment  
Unit Interface (AUI) port and four 10BASE-T transceivers. The AUI port is mode selectable:  
DTE mode allows connection of an external transceiver (10BASE2, 10BASE5, 10BASE-T or  
FOIRL) or a drop cable. MAU mode creates a MAU output allowing direct connection to  
another DTE interface. The 10BASE-T transceivers are entirely self-contained with internal  
filters which simplify the design work required for FCC-compliant EMI performance.  
An inter-repeater backplane interface allows 128 or more 10BASE-T ports to be cascaded  
together. In addition, a serial port provides information for network management.  
The LXT914 Repeater requires only a single 5-volt power supply due to an advanced CMOS  
fabrication process.  
Product Features  
Four integrated 10BASE-T transceivers  
Synchronous or asynchronous inter-  
repeater backplane supports “hot  
swapping”  
Inter-repeater backplane allows cascaded  
repeaters, linking 128 or more 10BASE-T  
ports  
and one AUI transceiver on a single chip  
Programmable DTE/MAU interface on  
AUI port  
Seven integrated LED drivers with four  
unique operational modes  
Serial port for selecting programmable  
On-chip transmit and receive filtering  
options  
Automatic partitioning of faulty ports,  
68-pin PLCC (Commercial or Extended  
enabled on an individual port basis  
temp range)  
Automatic polarity detection and correction  
100-pin PQFP (Commercial temp range)  
Programmable squelch level allows  
extended range in low-noise environments  
Applications  
LAN Repeaters  
Switched Repeater Clusters  
Integrated Repeaters  
Order Number: 248989, Revision: 003  
31-Oct-2005  
Legal Lines and Disclaimers  
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ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. EXCEPT AS PROVIDED IN  
INTEL'S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, INTEL ASSUMES NO LIABILITY WHATSOEVER, AND INTEL DISCLAIMS  
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RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER  
INTELLECTUAL PROPERTY RIGHT. Intel products are not intended for use in medical, life saving, life sustaining, critical control or safety systems, or  
in nuclear facility applications.  
Intel may make changes to specifications and product descriptions at any time, without notice.  
Intel Corporation may have patents or pending patent applications, trademarks, copyrights, or other intellectual property rights that relate to the  
presented subject matter. The furnishing of documents and other materials and information does not provide any license, express or implied, by  
estoppel or otherwise, to any such patents, trademarks, copyrights, or other intellectual property rights.  
The Intel® LXT914 Flexible Quad Ethernet Repeater may contain design defects or errors known as errata which may cause the product to deviate  
from published specifications. Current characterized errata are available on request.  
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.  
Copies of documents which have an order number and are referenced in this document, or other Intel literature may be obtained by calling  
1-800-548-4725 or by visiting Intel's website at http://www.intel.com.  
Intel and the Intel logo are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries.  
*Other names and brands may be claimed as the property of others.  
Copyright © 2005, Intel Corporation. All Rights Reserved.  
31-Oct-2005  
2
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Contents  
1.0 LXT914 Pin Assignments and Signal Descriptions....................................................................7  
2.0 Functional Description................................................................................................................14  
2.1  
2.2  
Introduction .........................................................................................................................14  
External Interfaces..............................................................................................................14  
2.2.1 10BASE-T Ports ....................................................................................................14  
2.2.2 AUI Port .................................................................................................................14  
2.2.3 Serial Port..............................................................................................................14  
2.2.4 Inter-Repeater Backplane......................................................................................15  
2.2.4.1 Synchronous IRB Operation ..................................................................15  
2.2.4.2 Asynchronous IRB Operation ................................................................15  
Internal Repeater Circuitry..................................................................................................15  
Initialization .........................................................................................................................16  
2.4.1 Local Management Mode Initialization ..................................................................16  
2.4.2 External Management Mode Initialization..............................................................19  
10BASE-T Port Operation ..................................................................................................20  
2.5.1 10BASE-T Reception.............................................................................................20  
2.5.1.1 Programmable Internal Squelch Level...................................................21  
2.5.1.2 Polarity Detection and Correction ..........................................................21  
2.5.2 10BASE-T Transmission .......................................................................................21  
2.5.3 10BASE-T Link Integrity Testing............................................................................21  
AUI Port Operation .............................................................................................................22  
2.6.1 AUI Reception........................................................................................................22  
2.6.2 AUI Transmission ..................................................................................................22  
2.6.3 AUI Mode Selection (DTE/MAU)............................................................................22  
Collision Handling ...............................................................................................................23  
Security Mode.....................................................................................................................23  
LED Display........................................................................................................................23  
2.3  
2.4  
2.5  
2.6  
2.7  
2.8  
2.9  
3.0 Application Information ..............................................................................................................27  
3.1  
Layout Requirements..........................................................................................................27  
3.1.1 The Twisted Pair Interface.....................................................................................27  
3.1.2 The RBIAS Pin.......................................................................................................27  
12-Port Hub Repeater.........................................................................................................27  
8-Port Print or File Server...................................................................................................28  
3.2  
3.3  
4.0 Test Specifications......................................................................................................................35  
5.0 Package Specifications...............................................................................................................40  
5.1  
Top-Label Marking..............................................................................................................42  
6.0 Product Ordering Information ....................................................................................................44  
Datasheet  
31-Oct-2005  
3
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figures  
1
2
3
4
5
6
7
8
9
Block Diagram .............................................................................................................................. 7  
Pin Assignments........................................................................................................................... 8  
Global State Machine .................................................................................................................17  
Partitioning State Machine..........................................................................................................18  
Integrated LED Driver Indications...............................................................................................26  
12-Port Application Schematic, 68-Pin PLCC Package (Sheet 1 of 4).......................................29  
12-Port Application Schematic, 68-Pin PLCC Package (Sheet 2 of 4).......................................30  
12-Port Application Schematic, 68-Pin PLCC Package (Sheet 3 of 4).......................................31  
12-Port Application Schematic, 68-Pin PLCC Package (Sheet 4 of 4).......................................32  
10 8-Port Application Schematic, LED Mode 1 with AUISEL = MAU (Sheet 1 of 2) .......................33  
11 8-Port Application Schematic, LED Mode 1 with AUISEL = MAU (Sheet 2 of 2) .......................34  
12 Serial Port Timing.......................................................................................................................38  
13 Inter-Repeater Bus Timing .........................................................................................................39  
14 LXT914PC/PE Package Specifications......................................................................................40  
15 LXT914QC Package Specifications ...........................................................................................41  
16 Sample PLCC Package - Intel® LXT914 Repeater ....................................................................42  
17 Sample Pb-Free (RoHS-Compliant) PLCC Package - Intel® LXT914 Repeater ........................42  
18 Sample PQFP Package - Intel® LXT914 Repeater ....................................................................43  
19 Sample Pb-Free (RoHS-Compliant) PQFP Package - Intel® LXT914 Repeater........................43  
20 Ordering Information Matrix – Sample........................................................................................45  
Tables  
1
Power, Ground, and Clock Signal Descriptions............................................................................ 9  
2
3
4
5
6
7
8
9
Inter-Repeater Backplane Signal Descriptions...........................................................................10  
Mode Select and Control Signal Descriptions ............................................................................10  
Serial Port Signal Descriptions (External Management Mode) ..................................................11  
Serial Port Signal Descriptions (Local Management Mode) .......................................................11  
Miscellaneous Control Signal Descriptions ................................................................................12  
LED Driver Signal Descriptions ..................................................................................................12  
Repeater Port Signal Descriptions .............................................................................................13  
Setup Register Bit Assignments.................................................................................................19  
10 Setup Register Bit Definitions.....................................................................................................19  
11 Packet Status Register Bit Assignments ....................................................................................20  
12 Packet Status Register Bit Definitions........................................................................................20  
13 AUI Mode Selection (DTE/MAU) ................................................................................................22  
14 LED Mode Selection...................................................................................................................24  
15 Mode 0 (Default) LED Truth Table .............................................................................................24  
16 Mode 1 LED Truth Table ............................................................................................................24  
17 Mode 2 LED Truth Table ............................................................................................................25  
18 Mode 3 LED Truth Table ............................................................................................................25  
19 Manufacturers Magnetics List.....................................................................................................28  
20 Absolute Maximum Ratings........................................................................................................35  
21 Recommended Operating Conditions ........................................................................................35  
22 I/O Electrical Characteristics1 .....................................................................................................35  
23 AUI Electrical Characteristics .....................................................................................................36  
24 Twisted-Pair Electrical Characteristics .......................................................................................36  
25 IRB Electrical Characteristics .....................................................................................................37  
31-Oct-2005  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
4
Intel® LXT914 Flexible Quad Ethernet Repeater  
26 Switching Characteristics............................................................................................................37  
27 Serial Port Timing—External Mode ............................................................................................37  
28 Inter-Repeater Bus Timing..........................................................................................................38  
29 Product Ordering Information .....................................................................................................44  
Datasheet  
31-Oct-2005  
5
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Revision History  
Date  
Revision  
Description  
Added Section 5.1 and Figure 16 through Figure 19 (RoHS top labels).  
31-Oct-2005  
003  
Added Section 6.0, “Product Ordering Information” on page 44 with Table 29 “Product Ordering  
Information” on page 44 and Figure 20 “Ordering Information Matrix – Sample” on page 45.  
Added Layout Requirements section under Application Information.  
Feb 2001  
002  
Modified I/O Electrical Characteristics table: Change Max value under Supply Current from 180  
to 240; Add text under Test Conditions: “100 test load, no LEDs”; add table note 3.  
31-Oct-2005  
6
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
1.0  
LXT914 Pin Assignments and Signal Descriptions  
Figure 1.  
Block Diagram  
FPS/SECAUI  
RESET  
LOC/EXT  
A/SYNC  
SYSCLK  
SENI  
SENO  
SDI  
SDO  
SCLK  
DOP  
DON  
Twisted-Pair  
Port #1  
Management Port  
(Serial I/F)  
Control  
DIP  
DIN  
4
4
4
DO/DI  
DO/DI  
DO/DI  
F
F
F
TP Port #2  
TP Port #3  
TP Port #4  
IRENA  
IRDEN  
IRCFS  
IRCOL  
IRDAT  
BCLKIO  
Repeater  
(State Machine, Timing  
Recovery, FIFO, etc.)  
Inter-Repeater  
Backplane Port  
DOP  
DON  
DIP  
DIN  
CIP  
CIN  
AUISEL*  
AUI Port  
4
*
The AUI Select function is provided on a dedicated  
(Mode selectable  
TP1 - 4  
AUI  
CF  
JM  
AUISEL pin in the 100-pin PQFP (LXT914QC). In the  
68-pin PLCC (LXT914PC/PE) the AUI Select function is  
provided through shared usage of the JM LED pin.  
DTE/MAU)  
LED Drivers  
Datasheet  
31-Oct-2005  
7
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 2.  
Pin Assignments  
Rev #  
Part #  
FPO #  
LXT914PC/PE XX  
XXXXXXXX  
BSMC  
B5381-01  
Part #  
FPO #  
Rev #  
XXXXXXXX  
BSMC  
B5382-01  
31-Oct-2005  
8
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 1.  
Power, Ground, and Clock Signal Descriptions  
Pin #  
Symbol I/O  
PLCC PQFP  
Description  
1
27  
61  
62  
69  
70  
88  
89  
90  
91  
93  
VCC1  
VCC2  
VCC3  
VCC4  
VCC5  
VCC6  
VCC7  
VCC8  
VCC9  
VCC10  
2
3
26  
49  
55  
67  
68  
Power Supply Inputs. These pins each require a +5 VDC power supply.  
The various pins may be supplied from a single power source, but special  
de-coupling requirements may apply. Each VCC input must be within ±0.3  
V of every other VCC input.  
9
39  
41  
43  
44  
58  
65  
66  
73  
99  
GND1  
GND2  
GND3  
GND4  
GND5  
GND6  
GND7  
GND8  
GND9  
34  
36  
38  
39  
46  
52  
58  
Ground. These pins provide ground return paths for the various power  
supply pins.  
Bias. This pin provides bias current for the internal circuitry. The 100 µA  
bias current is provided through an external 12.4 kΩ resistor to ground.  
37  
10  
11  
42  
RBIAS  
Backplane Clock. This 10 MHz clock synchronizes multiple repeaters on a  
common backplane. In the synchronous mode, BCLKIO must be supplied  
to all repeaters from a common external source. In the asynchronous  
4
BCLKIO I/O mode, BCLKIO is supplied only when a repeater is outputting data to the  
bus. Each repeater outputs its internally recovered clock when it takes  
control of the bus. Other repeaters on the backplane then sync to BCLKIO  
for the duration of the transmission.  
System Clock. The required 20 MHz system clock is input at this pin.  
Clock must have a 40-60 duty cycle with < 10 ns rise time.  
6
SYSCLK  
I
Datasheet  
31-Oct-2005  
9
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 2.  
Inter-Repeater Backplane Signal Descriptions  
PLCC PQFP Symbol I/O  
Description  
Inter-Repeater Backplane Enable. This pin allows individual LXT914  
4
5
94  
95  
IRENA  
IRDAT  
I/O repeaters to take control of the Inter-Repeater Backplane (IRB) data bus  
(IRDAT). The IRENA bus must be pulled up locally by a 330 Ω resistor.1  
IRB Data. This pin is used to pass data between multiple repeaters on the  
I/O  
IRB. The IRDAT bus must be pulled up locally by a 330 Ω resistor.1  
IRB Driver Enable. The IRDEN pin is used to enable external bus drivers  
which may be required in synchronous systems with large backplanes. This  
is an active Low signal, maintained for the duration of the data  
6
96  
IRDEN  
O
transmission. IRDEN must be pulled up locally by a 330 Ω resistor.  
IRB Collision Flag Sense (IRCFS) and IRB Collision (IRCOL). These two  
pins are used for collision signalling between multiple LXT914 devices on  
the Inter-Repeater Backplane (IRB). Both the IRCFS bus and the IRCOL  
7
8
97  
98  
IRCFS  
IRCOL  
I/O  
I/O  
bus must be pulled up globally with 330 Ω resistors. (IRCFS requires a  
precision resistor [±1%].)2  
NOTES:  
1. IRENA and IRDAT can be buffered between boards in multi-board configurations. Where buffering is used,  
a 330 Ω pull-up resistor can be used on each signal, on each board. Where no buffering is used, the total  
impedance should be no less than 330 Ω.  
2. IRCFS and IRCOL cannot be buffered. In multi-board configurations, the total impedance on IRCOL should  
be no smaller than 330 Ω. IRCFS should be pulled up only once, by a single 330 Ω, 1% resistor.  
Table 3.  
Mode Select and Control Signal Descriptions  
PLCC PQFP Symbol I/O  
Description  
Backplane Sync Mode Select. This pin selects the backplane sync mode.  
When this pin is left floating an internal pull-up defaults to the  
Asynchronous mode (A/SYNC High). In the asynchronous mode 12 or  
more LXT914s can be connected on the backplane, and an external 10  
MHz backplane clock source is not required. When the synchronous mode  
is selected (A/SYNC tied Low), 32 or more LXT914s can be connected to  
the backplane and an external 10 MHz backplane clock source is required.  
12  
13  
8
9
A/SYNC  
I
I
Management Mode Select. This pin selects the management mode. When  
this pin is left floating, an internal pull-up defaults to the Local management  
mode (LOC/EXT High). In the Local mode, setup parameters are  
downloaded from an EEPROM during initialization. Once initialized with the  
setup parameters, the repeater functions independently.  
LOC/EXT  
LED Driver or DTE/MAU Select. At reset, this pin selects the mode of the  
AUI port. If left floating, an internal pull-down device forces the AUI port to  
LEDJM/  
AUISEL  
28  
33  
30  
I/O DTE mode. If pulled High with an external resistor, the port changes to a  
MAU, in which case the functions of the LEDJM pin are disabled and the  
default LED mode (Refer to Table 7) is not available.  
DTE/MAU Select. This pin changes the mode of the AUI port independent  
of the condition at reset. This function is available only in the 100-pin PQFP  
AUISEL  
I
package.  
17  
35  
14  
40  
LED Mode 0 & 1 Select. These two pins select one of four possible LED  
modes of operation. The Functional Description section describes the four  
modes.  
LEDM0  
LEDM1  
I/O  
I/O  
31-Oct-2005  
10  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 4.  
Serial Port Signal Descriptions (External Management Mode)  
PLCC PQFP Symbol I/O  
Description  
Serial Enable Input. This active Low input is used to access the LXT914  
serial interface. To write to the serial input (SDI), an External Management  
Device (EMD) must drive this pin from High to Low. The input must be  
asserted Low concurrent with the appearance of data on SDI and remain  
Low for the duration of the serial input transaction.  
14  
11  
SENI  
I
Serial Enable Output. This active Low output is used to access the serial  
interface of an EMD. When the LXT914 sends a data stream to the EMD  
through the serial port (SDO), this output transitions from High to Low and  
remains Low for the duration of the serial transmission.  
15  
16  
12  
13  
SENO  
SDI  
O
I
Serial Data Input. This pin is the input for the EMD serial interface. Setup  
and operating parameters are supplied to the LXT914 in a serial data  
stream through this port when operating in the External Management  
Mode.  
Serial Data Output. After each packet transmission or interrupt event, the  
17  
18  
14  
16  
SDO  
I/O LXT914 reports status information to the EMD in a serial data stream  
through this port.  
Serial Clock. This 10 MHz clock synchronizes the serial interface between  
SCLK  
I
the LXT914 and the EMD. Both devices must be supplied from the same  
clock source. In synchronous mode, SCLK and BCLK may be tied together.  
Table 5.  
Serial Port Signal Descriptions (Local Management Mode)  
PLCC PQFP Symbol I/O  
Description  
Chip Select. The LXT914 is designed for use with an EEPROM or similar  
device which may be used to store setup parameters and serially download  
them to the LXT914 during initialization. In a single-device application or in  
the first device of a daisy chain application, this pin is an active High Chip  
Select output used to enable the EEPROM.  
CS  
O
I
14  
11  
Serial Enable Input. In subsequent devices of a daisy-chain configuration,  
a High-to-Low transition on this pin enables the serial input port (SDI). The  
input must be asserted concurrent with the appearance of data on SDI and  
remain Low for the duration of the serial input transaction.  
SENI  
Serial Enable Output. During initialization, the LXT914 accepts 48 bits of  
setup data through the SDI port. After the 48th bit, the LXT914 asserts this  
pin Low. When multiple LXT914 devices are connected in a daisy-chain,  
this output is tied to the SENI input of the next device in the chain. Thus  
each device in the chain is serially enabled by the previous device until all  
the devices have read in their 48 bits of setup data.  
15  
12  
SENO  
O
Setup Data Input. This pin is the serial input port for the setup parameters  
(48 bits).This pin should be tied Low if no EEPROM is present.  
16  
17  
13  
14  
SDI  
I
Request To Send. In a single-device application or in the first device of a  
daisy chain application, this pin outputs a 9-bit, active High sequence. This  
pin must be tied to the EEPROM DI input to trigger the EEPROM to  
download its stored data. In subsequent devices this pin is not used.  
RTS  
I/O  
Serial Clock. A 1 MHz clock provided by the first LXT914 in the chain to all  
18  
16  
SCLKIO I/O subsequent repeaters and the EEPROM. In the Local mode all repeaters  
have their SCLKIO pins tied together.  
Datasheet  
31-Oct-2005  
11  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 6.  
Miscellaneous Control Signal Descriptions  
PLCC PQFP Symbol I/O  
Description  
19  
20  
18  
19  
TEST  
I
I
Test Mode Select. This pin must be tied Low for normal operation.  
RESET. This pin resets the LXT914 circuitry when pulled High for 1 ms.  
RESET  
DSQE  
(Local)  
DSQE. In Local Mode, this pin controls the SQE function. When High, the  
SQE function of the AUI port is disabled. When Low, SQE is enabled.  
I
Security Mode Select (TP Port 1). In External Mode, this pin enables the  
security mode for twisted-pair port 1. When pulled High, the LXT914 Jams  
the port. This pin must be tied Low if external security control is not  
required.  
21  
21  
SECTP1  
(External)  
I
22  
23  
24  
SECTP2  
SECTP3  
SECTP4  
(External)  
Security Mode Select (TP Ports 2–4). In External Mode, these pins  
enable the security mode for the respective twisted-pair ports (TP1 through  
TP4). When pulled High, the LXT914 jams the affected port. The SEC pins  
must be tied Low if external security control is not required.  
22  
23  
24  
I
I
I
First Position Select. In the Local mode this pin identifies the first device  
in a daisy chain configuration. When tied High (First position), the LXT914  
controls the local EEPROM by providing clock and handshaking. When tied  
Low (Not First), the LXT914 will accept CLK and data in its turn from  
previous LXT914s in the data chain.  
FPS  
(Local)  
I
I
25  
25  
Security Mode Select (AUI Port). In the External mode this pin enables  
the security mode for the AUI port. When pulled High, the LXT914 jams the  
AUI port. The security feature is available only in External management  
mode.  
SECAUI  
(External)  
Table 7.  
LED Driver Signal Descriptions  
PLCC PQFP Symbol I/O  
Description  
Collision & FIFO Error LED Driver. This tri-state LED driver pin reports  
collisions and FIFO errors. It pulses Low to report collisions, and pulses  
High to report FIFO errors. When this pin is connected to the anode of one  
LED and to the cathode of a second LED, the LXT914 will simultaneously  
monitor and report both conditions independently.  
27  
28  
32  
33  
LEDCF  
LEDJM  
O
O
Jabber/MJLP & Manchester Code Violation LED Driver. This tri-state  
LED driver pin reports jabber and code violations. It pulses Low to report  
MAU Jabber Lockup Protection (MJLP), and pulses High to report  
Manchester code violations. When this pin is connected to the anode of  
one LED and to the cathode of a second LED, the LXT914 will  
simultaneously monitor and report both conditions independently.  
29  
30  
31  
32  
34  
35  
36  
37  
LEDTP1  
LEDTP2  
LEDTP3  
LEDTP4  
O
O
O
O
Twisted-Pair Port LED Drivers. These tri-state LED drivers use an  
alternating pulsed output to report TP port status. Each pin should be tied to  
a pair of LEDs (to the anode of one LED and the cathode of a second LED).  
When connected this way, each pin reports five separate conditions  
(receive, transmit, link integrity, reverse polarity and auto partition).  
AUI Port LED Driver. This tri-state LED driver uses an alternating pulsed  
output to report AUI port status. This pin should be tied to a pair of LEDs (to  
the anode of one LED and the cathode of a second LED). When connected  
this way, this pin reports five separate conditions (receive, transmit, receive  
jabber, receive collision and auto partition.  
33  
38  
LEDAUI  
O
31-Oct-2005  
12  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 8.  
Repeater Port Signal Descriptions  
PLCC PQFP Symbol I/O  
Description  
AUI Data Outputs (Positive and Negative). These pins are the positive  
and negative data outputs for the AUI Port. In MAU Mode these pins are  
connected to the DI pins of the DTE.  
40  
41  
46  
47  
AUIDOP  
AUIDON  
O
O
AUI Data Input (Positive and Negative). These pins are the positive and  
negative data inputs for the AUI Port. In MAU Mode, these pins are  
connected to the DO pins of the DTE.  
42  
43  
48  
49  
AUIDIP  
AUIDIN  
I
I
AUI Collision (Positive and Negative). These pins are the positive and  
negative Collision inputs for the AUI Port in DTE Mode. In MAU Mode,  
these pins output a collision indication to the DTE.  
44  
45  
54  
55  
AUICIP  
AUICIN  
I/O  
I/O  
56  
57  
71  
72  
TPDOP1  
TPDON1  
O
O
54  
53  
68  
67  
TPDOP2  
TPDON2  
O
O
Twisted-Pair Data Outputs (Positive and Negative). These pins are the  
positive (TPDOP1-4) and negative (TPDON1-4) outputs to the network  
from the respective twisted-pair ports.  
50  
51  
63  
64  
TPDOP3  
TPDON3  
O
O
48  
47  
60  
59  
TPDOP4  
TPDON4  
O
O
66  
65  
87  
86  
TPDIP1  
TPDIN1  
I
I
64  
63  
85  
84  
TPDIP2  
TPDIN2  
I
I
Twisted-Pair Data Inputs (Positive and Negative). These pins are the  
positive (TPDIP1-4) and negative (TPDIN1-4) inputs from the network to  
the respective twisted-pair ports.  
62  
61  
83  
82  
TPDIP3  
TPDIN3  
I
I
60  
59  
77  
76  
TPDIP4  
TPDIN4  
I
I
Datasheet  
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Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
13  
Intel® LXT914 Flexible Quad Ethernet Repeater  
2.0  
Functional Description  
2.1  
Introduction  
The LXT914 Repeater is an integrated hub repeater for 10BASE-T networks. The hub repeater is  
the central point for information transfer across the network. The LXT914 Repeater offers multiple  
operating modes to suit a broad range of applications ranging from simple 4-port stand-alone hubs  
or attachments for print and file servers, up to intelligent 128-port enterprise systems with  
microprocessor/gate arLXT914 Repeater ray management.  
The main functions of the LXT914 Repeater hub repeater are data recovery and re-transmission  
and collision propagation. Data packets received at the AUI or 10BASE-T ports are detected and  
recovered by the port receivers before being passed to the repeater core circuitry for re-timing and  
re-transmission. Data packets received through the IRB port are essentially passed directly to the  
core for retransmission. After recovery of a valid data packet, the repeater broadcasts it to all  
enabled stations, except the originator station.  
2.2  
External Interfaces  
The LXT914 Repeater includes four 10BASE-T ports with internal filters. The LXT914 Repeater  
also includes an Attachment Unit Interface (AUI) port, a serial port and an Inter-Repeater  
Backplane (IRB) port. The serial port allows an external device such as an EEPROM to download  
setup parameters to the repeater. In more complex designs the serial port can also be used to  
monitor repeater status. The IRB port enables multiple LXT914 Repeater devices to be cascaded,  
creating a large, multi-port repeater.  
2.2.1  
2.2.2  
2.2.3  
10BASE-T Ports  
The four 10BASE-T transceiver ports are completely self-contained. Since the transmitters and  
receivers include the required filtering, only simple, inexpensive transformers are required to  
complete the 10BASE-T interface. Each individual Twisted-Pair (TP) port is implemented in  
accordance with the IEEE 802.3 10BASE-T standard.  
AUI Port  
The AUI port mode is selectable (DTE mode or MAU mode). With DTE mode selected, the AUI  
port allows connection of an external transceiver (10BASE2, 10BASE5, 10BASE-T or FOIRL) or  
a drop cable. With MAU mode selected, the AUI port establishes a MAU output allowing direct  
connection to another DTE interface.  
Serial Port  
The serial port provides the management interface to the LXT914 Repeater. Refer to Test  
Specifications for serial port timing. The serial port can be either unidirectional or bidirectional,  
depending on the management mode selected. In the Local management mode the serial port is  
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Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
unidirectional (input only), and is used only to download setup parameters during initialization.  
The Local mode is intended for use with a simple EEPROM, but the serial port may be tied Low if  
an EEPROM is not required.  
In the External management mode, the serial port is bi-directional (input for setup parameters,  
output for status reports). The External mode is intended for use with an External Management  
Device (EMD) and a Media Access Controller (MAC). The EMD (typically a gate array)  
communicates with a microprocessor (e.g., Intel 8051) and can control up to three LXT914  
Repeaters. This simplifies design of a relatively standard 12-port repeater on a single printed circuit  
board.  
2.2.4  
Inter-Repeater Backplane  
The Inter-Repeater Backplane (IRB) allows several LXT914 Repeaters to function as a single  
repeater. Refer to Test Specifications for IRB timing. The IRB also allows several multi-repeater  
boards to be integrated in a standard rack and to function as a single unit. The IRB supports “hot  
swapping” for easy maintenance and troubleshooting. Each individual repeater distributes  
recovered and re-timed data to other repeaters on the IRB for broadcast on all ports simultaneously.  
This simultaneous rebroadcast allows the multi-repeater system to act as a single large repeater  
unit. The maximum number of repeaters on the IRB is limited by bus loading factors such as  
parasitic capacitance. The IRB can be operated synchronously or asynchronously.  
2.2.4.1  
2.2.4.2  
Synchronous IRB Operation  
In the synchronous mode, a common external source provides the 10 MHz backplane clock  
(BCLKIO) and the 20 MHz system clock (SYSCLK) to all repeaters. BCLKIO must be  
synchronous to SYSCLK and may be derived from SYSCLK using a divide-by-two circuit. In the  
synchronous mode 32 or more LXT914 Repeaters may be connected on the IRB, providing 128  
10BASE-T ports and 32 AUI ports.  
Asynchronous IRB Operation  
In the asynchronous mode an external BCLKIO source is not required. The repeaters run  
independently until one takes control of the IRB. The transmitting repeater then outputs its own 10  
MHz clock onto the BCLKIO line. All other repeaters sync to that clock for the duration of the  
transmission. In the asynchronous mode 12 or more LXT914 Repeater may be connected to the  
IRB, providing 48 10BASE-T ports and 12 AUI ports.  
The maximum number of repeaters which may be linked on the backplane is limited by board  
design factors. The numbers listed above are engineering estimates only. Stronger drivers and  
reduced capacitive loading in PCB layout may allow an increased device count.  
2.3  
Internal Repeater Circuitry  
The basic repeater circuitry is shared among all the ports within the LXT914 Repeater. It consists  
of a global repeater state machine, several timers and counters and the timing recovery circuit. The  
timing recovery circuit includes a FIFO for re-timing and recovery of the clock which is used to  
clock the receive data out onto the IRB.  
Datasheet  
31-Oct-2005  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
15  
Intel® LXT914 Flexible Quad Ethernet Repeater  
The shared functional blocks of the LXT914 Repeater are controlled by the global state machine  
(Figure 3). This diagram and all associated notations used are in strict accordance with section 9.6  
of the IEEE 802.3 standard.  
The LXT914 Repeater also implements the Partition State Diagram as defined by the IEEE 802.3  
standard and shown in Figure 4. The value of CCLimit as implemented in the LXT914 Repeater is  
64.  
The CCLimit value sets the number of consecutive collisions that must occur before the port is  
subjected to automatic partitioning. Auto-partition/re-connection is also supported by the  
LXT914 Repeater with Tw5 conforming to the standard requirement of 450 to 560 bit times.  
2.4  
Initialization  
The following description applies to the initial power-on reset and to any subsequent hardware  
reset. When a reset occurs (RESET pin pulled High for > 1 ms), the device senses the levels at the  
various control pins (see Figure 3) to determine the correct operating modes for Management,  
LEDs, and the AUI port functions.  
2.4.1  
Local Management Mode Initialization  
An internal pull-up causes the LXT914 Repeater to default to the Local management mode unless  
the LOC/EXT pin is tied Low. In the Local mode the serial port is a unidirectional interface used  
only to download setup parameters from an external device.  
In a Locally managed multiple-repeater (daisy chain) configuration, the first repeater in the chain  
performs special functions. The First Position Select (FPS) pin is used to establish position (FPS  
High = First, FPS Low = Not First). After establishing the Hardware mode, each LXT914 Repeater  
monitors the FPS pin to determine its position.  
If FPS is High (First Position), the repeater performs the following functions:  
Outputs a 1 MHz Serial Clock (SCLK). SCLK is derived from the 20 MHz SYSCLK input in  
ASYNC mode and from BCLKIO in SYNC mode; it is supplied to the SCLK inputs of all other  
repeaters on the bus and to the EEPROM.  
Asserts Chip Select (CS) High to enable the EEPROM.  
Outputs a serial 9-bit request-to-send (RTS) strobe. The programmable device responds to the RTS  
strobe with a serial data stream containing the setup parameters for all repeaters in the chain.  
Clocks the first 48 serial data input (SDI) bits from the EEPROM into its setup register. Refer to  
Table 9 and Table 10 for Setup Register bit assignments.  
Asserts Serial Enable Output (SENO) Low to enable the next repeater in line.  
The second repeater has FPS tied Low and Serial Enable Input (SENI) connected to the Serial  
Enable Output (SENO) of the first repeater. When enabled by a Low on SENI, each repeater  
downloads its portion of the stream, then stops accepting data and asserts SENO Low. The SENO  
pin is linked to the SENI input of the next repeater. This enables the next repeater to clock in its 48-  
bit word and so on.  
If FPS is Low (Not First Position), the repeater performs the following functions:  
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Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
1. Syncs to the 1 MHz Serial Clock (SCLK) input. SCLK is supplied by the First Position  
repeater.  
2. Responds to SENI Low by enabling the SDI port.  
3. Clocks 48 bits from the EEPROM into its setup register through the SDI port.  
4. Asserts SENO Low to enable the next repeater in line.  
Figure 3.  
Global State Machine  
Power On  
START  
Begin  
UCT  
IDLE  
Out (ALL) = Idle  
Collin(ANY) = SQE[N Port(Collin = SQE)]  
Datain(ANY) = II * Collin(ALL) = SQE:[N Port(Datain = II)]  
SEND PREAMBLE PATTERN  
Out (ALLXN) = Preamble Pattern  
Collin(ANYXN) = SQE  
TT(ALLXN)  
Collin(N) = SQE + Datain(N) = II * Collin(ALL) = SQE  
62 * DataRdy * Collin(ALL) = SQE * Datain(N) = II  
SEND TWO ONES  
Out (ALLXN) = TwoOnes  
Collin(ANYXN) = SQE  
Collin(N) = SQE + Datain = II * Collin(ALL) = SQE  
TwoOnesSent * Collin(ALL) = SQE * Datain(N) = II  
SEND DATA  
Out (ALLXN) = Data  
Collin(N) = SQE + Datain(N) = II *  
Collin(ANYXN) = SQE  
Collin(ALL) = SQE *  
AllDataSent * TT(ANAYXN) < 96  
TRANSMIT COLLISION  
RECEIVE COLLISION  
Out (All) = Jam  
Out (ALLXN) = Jam  
Collin(ANYXN) = SQE  
Collin(ALL) = SQE * TT(ALL) 96 * Tw2Done  
Datain(N) = II *  
Collin(ALL) = SQE *  
TT(ALLXN) 96 *  
Tw2Done  
Datain(N) = II *  
Collin(ALL) = SQE *  
TT(ALLXN) 96 *  
AllDataSent  
Collin(ONLY1) = SQE *  
TT(ALL) 96:[M Port(Collin = SQE)]  
ONE PORT LEFT  
Out (ALLXM) = Jam  
Collin(ANYXM) = SQE  
Datain(M) = II*  
Collin(ALL) = SQE*  
Tw2Done  
WAIT  
StartTw1  
Out(ALL) = Idle  
Collin(ANY) = SQE + Tw1Done  
Datasheet  
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Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 4.  
Partitioning State Machine  
Begin  
COUNT CLEAR  
CC(X) = 0  
Datain(X) = DIPresent(X)  
Collin(X) = CIPresent(X)  
DIPresent(X) = II *  
CIPresent(X) = SQE  
COLLISION COUNT IDLE  
Datain(X) = DIPresent(X)  
Collin(X) = CIPresent(X)  
PARTITION WAIT  
DIPresent(X) = II + CIPresent(X) = SQE  
Datain(X) = II  
Collin(X) = SQE  
WATCH FOR  
COLLISION  
StartTw5  
DIPresent(X) = II *CIPresent(X) = SQE  
Datain(X) = DIPresent(X)  
Collin(X) = CIPresent(X)  
PARTITION HOLD  
DIPresent(X) = II *  
Datain(X) = II  
CIPresent(X) = SQE  
Collin(X) = SQE  
CIPresent(X) = SQE  
Tw5Done * DIPresent(X) = II *  
CIPresent(X) = SQE  
DIPresent(X) = II + CIPresent(X) = SQE  
COLLSION COUNT  
INCREMENT  
PARTITION COLLISION  
WATCH  
CC(X) = CC(X) + 1  
Datain(X) = DIPresent(X)  
Datain(X) = II  
Collin(X) = CIPresent(X)  
StartTw6  
Collin(X) = SQE  
StartTw5  
CC(X)  
CCLimit + (Tw6Done *  
CIPresent(X) = SQE)  
DIPresent(X) = II *  
CIPresent(X) = SQE *  
CC(X) < CCLimit *  
Tw6Done  
CIPresent(X) =  
SQE  
DIPresent(X) = II  
CIPresent = SQE  
Tw5Done * DIPresent(X) = II *  
CIPresent(X) = SQE  
WAIT TO RESTORE  
PORT  
Datain(X) = II  
Collin(X) = SQE  
CC(X) = 0  
DIPresent(X) = II * CIPresent (X) = SQE  
31-Oct-2005  
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Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 9. Setup Register Bit Assignments  
Register  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
SR(0)  
SR(1)  
SR(2)  
SR(3)  
SR(4)  
SR(5)  
DISLI3  
DISTX2  
ERSQ1  
DFIFOE  
RES  
DISLI2  
DISTX1  
DISRX4  
DPFRM  
RES  
DISLI1  
DISTXA  
DISRX3  
DSQE  
RES  
DISAP4  
DPRC4  
DISRX2  
DMCV  
RES  
DISAP3  
DPRC3  
DISRX1  
ERXJAB  
RES  
DISAP2  
DPRC2  
DISRXA  
ERSQ4  
RES  
DISAP1  
DPRC1  
DISTX4  
ERSQ3  
RES  
DISAPA  
DISLI4  
DISTX3  
ERSQ2  
RES  
RES  
RES  
RES  
RES  
RES  
RES  
RES  
RES  
Table 10. Setup Register Bit Definitions  
Bit  
Definition  
DISAPx 1 = Disable Auto-Partitioning on Port x  
DISLIx 1 = Disable Link Integrity on Port x (Twisted-pair ports only)  
DPRCx 1 = Disable Polarity Reverse detection and Correction on Port x (Twisted-pair ports only)  
DISTXx 1 = Disable Transmit on Port x  
DISRXx 1 = Disable Receive on Port x  
ERSQx 1 = Enable Reduced Squelch on Port x (Twisted-pair ports only)  
ERXJAB 1 = Enable Receive JAB (Long Packet) (Global)  
DMCV  
DSQE  
1 = Disable entering Tx Collision state on reception of Manchester Code Violation  
1 = Disable Signal Quality Error to provide heartbeat (AUI port only)  
DPFRM 1 = Disable End-of-Frame checking for polarity correction (Global)  
DFIFOE 1 = Disable entering Tx Collision state on FIFO over/underflow condition (Global)  
DMJLP 1 = Disable MJLP counter (Global)  
RES  
Reserved. Must be set to 0.  
2.4.2  
External Management Mode Initialization  
The LXT914 Repeater operates in the External management mode when the LOC/EXT pin is tied  
Low. In the External mode, the serial port is a bidirectional interface between the  
LXT914 Repeater and an external management device (EMD). The serial port is used to download  
initial setup parameters to the repeater and to monitor status reports from the repeater. The  
LXT914 Repeater setup parameters can be changed at any time by the EMD. The initialization  
process for each repeater in a managed mode configuration is the same, regardless of its position;  
each repeater is connected directly to the EMD. Each LXT914 Repeater initializes as follows:  
1. Syncs to the 10 MHz Serial Clock (SCLK) input. SCLK must be supplied from an external  
source.  
2. Responds to SENI Low by enabling the SDI port.  
3. Clocks 48 bits from the EMD into its setup register through the SDI port.  
4. Once initialized, the LXT914 Repeater reports its status in a 48-bit serial stream after every  
packet transmission or interrupt event. Refer to Table 11 and Table 12 for packet status register  
bit assignments and definitions.  
Datasheet  
31-Oct-2005  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
19  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 11. Packet Status Register Bit Assignments  
Register  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
PSR(0)  
PSR(1)  
PSR(2)  
PSR(3)  
PSR(4)  
PSR(5)  
COL2  
PR2  
COL1  
PR1  
COLA  
LLS4  
RX4  
LLS3  
RX3  
LLS2  
RX2  
LLS1  
RX1  
COL4  
PR4  
RXA  
COL3  
PR3  
SPA  
AP4  
AP3  
AP2  
AP1  
APA  
LP3  
LP2  
LP1  
LPA  
SP4  
SP3  
SP2  
SP1  
RXJABA  
RES  
MJLP  
RXCOL  
LCOL4  
MANCV  
LCOL3  
FIFOER  
LCOL2  
RXJAB4  
LCOL1  
RXJAB3  
LCOLA  
RXJAB2  
LP4  
RXJAB1  
Table 12. Packet Status Register Bit Definitions  
1
Bit  
Definition  
RXx  
Received Packet on Twisted-Pair Port 1-4 or on AUI Port  
Transmit Collision of Twisted -Pair Port 1-4 or on AUI Port  
COLx  
LLSCx Link Loss State on Twisted-Pair Port 1-4 or on AUI Port  
PRx  
APx  
SPx  
LPx  
Polarity reversed on Twisted-Pair Port 1-4 or on AUI Port  
Auto-Partition circuit isolated Twisted-Pair Port 1-4 or the AUI Port  
Short Packet (less than 74 bits) on Twisted-Pair Port 1-4 or on AUI Port  
Long Packet (more than 1.3 ms) on Twisted-Pair Port 1-4 or on AUI Port  
LCOLx Late Collision on Twisted-Pair Port 1-4 or on AUI Port  
MJLP MAU Jabber Lockup Protection  
RXJABx Receive Jabber Lockup Protection  
FIFOER FIFO overflow/underflow  
MANCV Manchester Code Violation  
RXCOL Receive Collision on the AUI Port  
RES  
Reserved. Not used  
Note:  
1.  
The notation ABCDx means bit ABCD associated with port x, which can be any of the four Twisted-  
Pair Ports or the AUI Port.  
2.5  
10BASE-T Port Operation  
2.5.1  
10BASE-T Reception  
Each LXT914 Repeater 10BASE-T port receiver acquires data packets from its twisted-pair input  
(TPDIP/TPDIN). An internal RC filter and an intelligent squelch function discriminate noise from  
link test pulses and valid data streams. The receive function is activated only by valid data streams  
(above the squelch level and with proper timing). If the differential signal at the DI circuit inputs  
falls below 75% of the threshold level (unsquelched) for eight bit times (typical), the port receiver  
enters the idle state.  
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Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
2.5.1.1  
2.5.1.2  
Programmable Internal Squelch Level  
The 10BASE-T port receivers have two squelch levels: a normal level or default setting and a  
reduced level squelch (-4.5 dB) selected when the ERSQx is set in the Setup register. When used  
with Low noise media such as shielded twisted-pair cabling, the reduced squelch level allows  
longer loop lengths in the network.  
Polarity Detection and Correction  
The LXT914 Repeater 10BASE-T ports detect and correct for reversed polarity by monitoring link  
pulses and end-of-frame sequences. A reversed polarity condition is declared when the port  
receives sixteen or more incorrect link pulses consecutively, or four frames with reversed start-of-  
idle sequence. In these cases the receiver reverses the polarity of the signal and thereby corrects for  
this failure condition. If the port enters the link fail state and no valid data or link pulses are  
received within 96 to 128 ms, the polarity is reset to the default non-flipped condition. (If Link  
Integrity Testing is disabled, polarity detection is based only on received data.)  
2.5.2  
10BASE-T Transmission  
Each LXT914 Repeater 10BASE-T port receives NRZ data from the repeater core and passes it  
through a Manchester encoder. The encoded data is then transmitted to the twisted-pair network  
(the DO circuit). The advanced integrated pulse shaping and filtering network produces the pre-  
distorted and pre-filtered output signal to meet the 10BASE-T jitter template. An internal  
continuous resistor-capacitor filter is used to remove any high-frequency clocking noise from the  
pulse shaping circuitry. Integrated filters simplify the design work required for FCC compliant  
EMI performance. During idle periods, the LXT914 Repeater 10BASE-T ports transmit link  
integrity test pulses in accordance with the 802.3 10BASE-T standard.  
Data packets transmitted by the LXT914 Repeater contain a minimum of 56 preamble bits before  
the start of frame delimiter (SFD). In the Asynchronous mode, preamble regeneration takes place  
on the transmit side. In the Synchronous mode, the preamble is regenerated on the receive side and  
distributed via the IRB. If the total packet is less than 96 bits including the preamble, the  
LXT914 Repeater extends the packet length to 96 bits by appending a Jam signal (1010...) at the  
end.  
2.5.3  
10BASE-T Link Integrity Testing  
The LXT914 Repeater fully supports the 10BASE-T Link Integrity test function. The link integrity  
test determines the status of the receive side twisted-pair cable. Link integrity testing is enabled  
unless disabled via the DISLIx bit in the Setup register. When enabled, the receiver recognizes link  
integrity pulses transmitted in the absence of data traffic. With no data packets or link integrity  
pulses within 100 (±50) ms, the port enters a link fail state and disables its transmitter. The port  
remains in the link fail state until it detects three or more data packets or link integrity pulses.  
Datasheet  
31-Oct-2005  
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Order Number: 248989, Revision: 003  
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Intel® LXT914 Flexible Quad Ethernet Repeater  
2.6  
AUI Port Operation  
2.6.1  
AUI Reception  
The LXT914 Repeater AUI port receiver acquires data packets from the network (AUIDIP/  
AUIDIN). Only valid data streams above the squelch level activate the receive function. If the  
differential signal at the DI circuit inputs falls below 75% of the threshold level (unsquelched) for 8  
bit times (typical), the AUI receiver enters the idle state.  
2.6.2  
2.6.3  
AUI Transmission  
The LXT914 Repeater AUI port receives NRZ data from the repeater core, and passes it through a  
Manchester encoder. The encoded data then goes out on the network (AUIDOP/AUIDON).  
AUI Mode Selection (DTE/MAU)  
The LXT914 Repeater allows the user to change the mode of the AUI from a DTE to a MAU  
interface. This option is available on both 68- and 100-pin versions except as follows:  
When using the LEDJM/AUISEL pin to select the AUI interface mode the following is true:  
After reset the state of the LEDJM/AUISEL pin is sensed for the correct mode. The LEDJM/  
AUISEL pin when floated or pulled Low will select the DTE interface and the LEDJM/  
AUISEL output is still available. When the LEDJM/AUISEL pin is pulled High the MAU  
interface is selected and the LEDJM/AUISEL function is unavailable.  
The 100-pin PQFP has an additional pin, AUISEL (pin 30). When using this pin to select the  
AUI interface mode the LEDJM/AUISEL pin is still a functional LED driver. The AUISEL  
pin is not latched after reset and is actively polled to determine which AUI interface mode is to  
be used. Refer to Table 13.  
Table 13. AUI Mode Selection (DTE/MAU)  
LEDJM/  
AUISEL  
(both pkgs)  
Available  
LED  
Modes  
AUISEL  
(PQFP only)  
App #  
AUI Mode  
1
2
3
4
Low  
Low  
High  
High  
Low  
High  
Low  
High  
DTE  
MAU  
MAU  
MAU  
default, 0-3  
1-3  
default, 0-3  
1-3  
Note: Application 3 is valid only when using the 100-pin PQFP.  
31-Oct-2005  
22  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
2.7  
Collision Handling  
A collision occurs when two or more repeater ports receive simultaneously, or when the AUI CIP/  
CIN signal is active. The LXT914 Repeater fully complies with the IEEE 802.3 collision  
specifications, both in individual and multi-repeater applications. In multiple-repeater  
configurations, collision signaling on the IRB allows all repeaters to share collision parameters,  
acting as a single large repeater.  
IRCOL is a digital open-drain pin. IRCFS is an analog/digital port. The IRCOL and IRCFS lines  
are pulled up globally (i.e., each signal requires one pull-up resistor for all boards). If there are  
eight 3-repeater boards in the system, all eight boards share a single pull-up resistor for IRCOL and  
a single pull-up resistor for IRCFS. The global pull-up may be located on one of the boards, or on  
the backplane. The IRCFS line requires a precision (± 1%) resistor.  
The IRENA, IRDAT and IRDEN lines are each pulled up locally (one pull-up resistor per board) if  
external bus drivers are used. If no bus drivers are used then only one global pull-up per signal is  
used.  
2.8  
Security Mode  
The LXT914 Repeater security mode is fully transparent to the user. In the External management  
mode, the security feature is available for all four TP ports and the AUI port. In the Local mode,  
security is available for the TP ports only (the SECAUI input is reassigned as FPS). The security  
inputs are normally held Low to disable the security feature. Any input can independently be pulled  
High to scramble the respective port for any given length of time. For applications which do not  
require security control, the SEC pins must be tied Low.  
The security mode pins are real time response inputs. This allows the board designer to screen the  
destination address with an application specific device and (on match of the destination address) to  
assert the security input to jam the respective port for the given frame. This real time detection and  
jam assertion method provides the flexibility to implement customer specific solutions. The  
destination address decoding and security signal assertion functions can be integrated into the  
external management device.  
2.9  
LED Display  
The LED display interface consists of seven integrated LED drivers, one for each of the five  
network ports and two for common functions. Each pin provides a three-state pulsed output (+5 V,  
high Z, and 0 V) which allows multiple conditions to be monitored and reported independently.  
Table 14 shows the LED Mode selected with each LEDM1 and LEDM0 combination. Figure 5  
shows the LED Driver output conditions, and Table 15 through Table 18 list the repeater states  
associated with each of the five conditions.  
Note: If LED mode 0 is selected and the LEDJM/AUISEL pin is High (which selects MAU Mode), the  
device defaults to LED Mode 1. LED Mode 0 is not available when LEDJM/AUISEL is pulled  
High.  
Datasheet  
31-Oct-2005  
23  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 14.  
LED Mode Selection  
LEDM1  
LEDM0  
17  
LED Mode  
Selected  
PLCC pin  
PQFP pin  
35  
40  
14  
0
Low  
Low  
Note 1  
Low  
High  
High  
High  
Low  
High  
1
2
3
Note:  
1.  
This mode is not available when using the LEDJM/AUISEL pin to  
select a MAU interface in the AUI port. In this case, the LED Mode  
defaults to LED Mode 1.  
LED Mode 0 (Default)  
This mode is selected when LEDM1 and LEDM0 are floating or pulled  
Low. Refer to Table 15. This mode is not available when using the  
LEDJM/AUISEL pin to select a MAU interface in the AUI port. In this case,  
the LED Mode defaults to Mode 1.  
LED Mode 1  
LED Mode 2  
LED Mode 3.  
This mode is selected when LEDM1 is floating or pulled Low and LEDM0  
is pulled High by a pull-up resistor. Refer to Table 16.  
This mode is selected when LEDM1 is pulled High by a pull-up resistor  
and LEDM0 is floating or pulled Low. Refer to Table 17.  
This mode is selected when LEDM1 is pulled High by a pull-up resistor  
and LEDM0 is also pulled High by a pull-up resistor. Refer to Table 18.  
Table 15.  
Mode 0 (Default) LED Truth Table  
Condition  
LEDTP 1–4  
LEDAUI  
LEDCF  
LEDJM  
1
2
Rx Link Pulse  
Tx Packet  
N/A  
FIFO Error  
N/A  
Manchester Code Violation  
N/A  
Tx Packet  
MAU Jabber Lockup  
Protection (MJLP)  
3
Reversed Polarity  
N/A  
Collision  
4
5
Rx Packet  
Rx Packet  
N/A  
N/A  
N/A  
N/A  
Partitioned Out  
Partitioned Out  
Table 16.  
Mode 1 LED Truth Table  
Condition  
LEDTP 1–4  
LEDAUI  
LEDCF  
LEDJM  
MAU Jabber Lockup  
Protection (MJLP)  
1
Rx Link Pulse  
N/A  
N/A  
2
3
4
5
N/A  
N/A  
N/A  
N/A  
N/A  
Collision  
N/A  
N/A  
N/A  
N/A  
N/A  
Rx Packet  
N/A  
Rx Packet  
N/A  
N/A  
31-Oct-2005  
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Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 17.  
Mode 2 LED Truth Table  
Condition  
LEDTP 1–4  
LEDAUI  
LEDCF  
LEDJM  
MAU Jabber Lockup  
Protection (MJLP)  
1
Rx Link Pulse  
N/A  
N/A  
2
3
4
5
Partitioned Out  
N/A  
Partitioned Out  
N/A  
N/A  
Collision  
N/A  
N/A  
N/A  
N/A  
N/A  
Rx Packet  
N/A  
Rx Packet  
N/A  
N/A  
Table 18.  
Mode 3 LED Truth Table  
Condition  
LEDTP 1–4  
LEDAUI  
LEDCF  
LEDJM  
MAU Jabber Lockup  
Protection (MJLP)  
1
Rx Link Pulse  
N/A  
N/A  
2
3
4
5
Rx Packet  
Partitioned Out  
N/A  
Rx Packet  
Partitioned Out  
N/A  
N/A  
Collision  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
Datasheet  
31-Oct-2005  
25  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 5.  
Integrated LED Driver Indications  
+5 V  
820  
+5 V  
330  
2 mA Operation  
5 mA Operation  
Ω
Ω
Ω
Red  
Red  
LXT914  
LED  
Driver  
LXT914  
LED  
Driver  
470  
820  
70  
Ω
Green  
Green  
Ω
330  
Ω
Condition 1:  
Steady Green  
+5V  
4 ms 4 ms  
4 ms  
4 ms 4 ms  
4 ms 4 ms  
High Z  
0V (Gnd)  
Condition 2:  
Blinking Green  
256 ms  
256  
ms  
+5V  
High Z  
0V (Gnd)  
4 ms  
4 ms 4 ms  
4 ms 4 ms  
4 ms 4 ms  
Condition 3:  
Steady Red  
+5V  
High Z  
0V (Gnd)  
4 ms 4 ms  
4 ms  
4 ms  
4 ms 4 ms  
Condition 4:  
Blinking Red  
256 ms  
+5V  
High Z  
0V (Gnd)  
256 ms  
4 ms 4 ms  
4 ms 4 ms  
4 ms 4 ms  
4 ms 4 ms  
5.33 Hz  
Condition 5:  
Alternating Red/Green  
+5V  
High Z  
0V (Gnd)  
4 ms 4 ms  
4 ms 4 ms  
4 ms  
4 ms  
4 ms  
93.75 ms  
31-Oct-2005  
26  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
3.0  
Application Information  
3.1  
Layout Requirements  
3.1.1  
The Twisted Pair Interface  
The four, twisted-pair output circuits are identical. Each TPDOP/TPDON signal has a 24.9 Ω, 1%,  
series resistor and a 120pF capacitor differentially across the positive and negative outputs. These  
signals go directly to a 1:2 transformer creating the necessary 100 Ω termination for the cable.  
The TPDIP/TPDIN signals have a 100 Ω resistor across the positive and negative input signals to  
terminate the 100 Ω signal received from the line. To calculate the impedance on the output line  
interface, use:  
(24.9 Ω + 24.9 Ω) 22 100 Ω.  
*
The layout of the twisted-pair ports is critical in complex designs. Run the signals directly from the  
device to the discrete termination components (located close to the transformers).  
The signals running from the transformers to the connector should run in close pairs directly to the  
connector. Be careful not to cross the transmit and receive pairs. One way to avoid a problem is to  
run the receive pairs on the component side and the transmit pairs on the solder side. Careful  
planning during the schematic and layout stages can avoid these problems.  
The PCB layout should have no ground or power planes from the transformers to the connectors.  
The data signals should be the only traces in this area. Place the chassis ground for the connectors  
near the edge of the PCB, away from the signals, connecting the connector shield with the chassis.  
3.1.2  
The RBIAS Pin  
The RBIAS signal sets the levels for the output drivers of the LXT914 Repeater. Any emissions or  
common mode noise entering the device here could be measured on the twisted pair output signals.  
The LXT914 Repeater requires a 12.4 kΩ, 1% resistor directly connected to RBIAS. This  
connection should be as short as possible. The ground rails from the adjacent ground pins should  
come directly off of the device to enclose the resistor and pin forming a shielded area between the  
RBIAS connection and the switching signals on the PCB.  
3.2  
12-Port Hub Repeater  
Figure 6 through Figure 9 (Sheets 1 through 4) show a simple 12-port hub repeater application with  
three LXT914 Repeaters. This application also provides two additional AUI ports—one DB-15  
connector and one coaxial port. The application shown uses the asynchronous backplane mode so  
no external backplane clock source is required.  
Figure 6 (Sheet 1) shows the XL93C46 EEPROM which downloads the setup parameters for all  
the LXT914 Repeater devices at initialization. (This EEPROM could be replaced with a simple  
pull down resistor on the SDI pin. This will select the default conditions of the set up register.) A  
single 20 MHz crystal provides the SYSCLK for all three LXT914 Repeater. The  
LXT914 Repeater hub repeater on Sheet 1 provides the AUI DB-15 connector as well as four  
twisted-pair ports. Table 19 lists transformers suggested for use with the LXT914 Repeater.  
Datasheet  
31-Oct-2005  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
27  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 7 (Sheet 2) shows a second LXT914 Repeater hub repeater with four TP ports and a coaxial  
port. The MD-001 coax transceiver is used to implement the port. Figure 8 (Sheet 3) shows the  
third LXT914 Repeater device with its four TP ports and indicator LEDs. The AUI port of the third  
LXT914 Repeater is not used. Figure 9 (Sheet 4) of the schematic shows the LEDs for the  
remaining LXT914 Repeaters, along with the LED operation table.  
3.3  
8-Port Print or File Server  
Figure 10 and Figure 11 (Sheets 1 and 2) show an eight-port repeater attachment for an existing  
single port AUI or 10BASE5 interface. This application can be added to a current design with an  
existing AUI or 10BASE5 interface. This circuit allows increased connectivity without the need for  
another external remote hub. The application shown is a 68-pin PLCC, an asynchronous backplane  
with both LXT914 Repeaters in the first position.  
In Figure 10 (Sheet 1) the LXT914 Repeater is set up with the LEDs in Mode 1 with one LED per  
port and a single collision LED. The twisted pair port LEDs display link integrity only. (Refer to  
Table 16.) LED Mode 1 is selected by pulling LEDM0 High with a 1 kΩ resistor on pin 17 and  
pulling LEDM1 Low with pin 35 attached to ground.  
Figure 11 (Sheet 2) has the same configuration, mode of operation and LED Mode as used in Sheet  
1. However, the AUI port has been configured as a MAU interface. This is selected when LEDJM/  
AUISEL on pin 28 is pulled up through a 1 kΩ resistor. This mode disables the LEDJM pin as an  
LED driver. (See Table 13.) The MAU interface now configured on the LXT914 Repeater allows  
the AUI port to attach to a DTE interface. This application increases connectivity to any existing  
single-port Ethernet design. This unique application allows the designer to integrate an external  
hub, eliminating the need for additional external equipment.  
Table 19. Manufacturers Magnetics List  
Manufacturer Quad Transmit Quad Receive  
Tx/Rx Pairs  
Bell Fuse  
Fil-Mag  
HALO  
S553-5999-02  
23Z339  
S553-5999-03  
23Z338  
TD54-1006L1  
TG54-1006N2  
TD01-1006L1 TD42-2006Q; TD43-2006K; TG42-1406N1  
TG01-1006N2 TG43-1406N  
TG44-S010NX  
(Octal)  
Kappa  
TP4003P  
5976  
TP497P101  
5977  
Nanopulse  
PCA  
EPE6009  
PE68810  
PT4116  
EPE6010  
PE68820  
PT4117  
Pulse Eng.  
VALOR  
PE65745; PE65994; PE65746; PE65998  
PT4069N1; PT4068N1; ST7011S2; ST7010S2  
31-Oct-2005  
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Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 6.  
12-Port Application Schematic, 68-Pin PLCC Package (Sheet 1 of 4)  
Datasheet  
31-Oct-2005  
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Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 7.  
12-Port Application Schematic, 68-Pin PLCC Package (Sheet 2 of 4)  
31-Oct-2005  
30  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 8.  
12-Port Application Schematic, 68-Pin PLCC Package (Sheet 3 of 4)  
Datasheet  
31-Oct-2005  
31  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 9.  
12-Port Application Schematic, 68-Pin PLCC Package (Sheet 4 of 4)  
31-Oct-2005  
32  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 10.  
8-Port Application Schematic, LED Mode 1 with AUISEL = MAU (Sheet 1 of 2)  
Datasheet  
31-Oct-2005  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
33  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 11.  
8-Port Application Schematic, LED Mode 1 with AUISEL = MAU (Sheet 2 of 2)  
31-Oct-2005  
34  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
4.0  
Test Specifications  
Note: Table 20 through Table 28 and Figure 12 and Figure 13 represent the performance specifications of  
the LXT914. These specifications are guaranteed by test except where noted “by design.”  
Minimum and maximum values listed in Table 22 through Table 28 apply over the recommended  
operating conditions specified in Table 21.  
Table 20.  
Absolute Maximum Ratings  
Parameter  
Symbol Min  
Typ  
Max Units  
Supply voltage  
VCC  
TOP  
TOP  
TST  
-0.3  
0
6
V
LXT914PC/QC  
LXT914PE  
+70  
+85  
+150  
° C  
° C  
° C  
Operating temperature  
-40  
-65  
Storage temperature  
Caution:  
Exceeding these values may cause permanent damage. Functional operation  
under these conditions is not implied. Exposure to maximum rating conditions  
for extended periods may affect device reliability.  
Table 21.  
Recommended Operating Conditions  
Parameter  
Symbol Min  
Typ  
Max Units  
Recommended supply voltage  
VCC  
TOP  
TOP  
4.75  
0
5.0  
5.25  
+70  
+85  
V
LXT914PC/QC  
LXT914PE  
° C  
° C  
Recommended operating temperature  
-40  
Table 22.  
I/O Electrical Characteristics1 (Sheet 1 of 2)  
Parameter  
Supply current  
Symbol  
Min  
Typ2  
Max  
Units  
Test Conditions  
ICC  
VIL  
240  
0.8  
0.8  
mA  
V
100Ω test load, no LEDs  
Input Low voltage  
Input Low voltage (RESET)  
Input High voltage  
VILRESET  
VIH  
V
VCC = 5.25 V  
2.0  
4.0  
V
Input High voltage (RESET)  
Output Low voltage  
Output Low voltage  
Output Low voltage (LED)  
Output High voltage  
Output High voltage  
Output High voltage (LED)  
NOTES:  
VIHRESET  
VOL  
V
VCC = 4.75 V  
IOL = 1.6 mA  
0.4  
10  
1.0  
V
VOL  
% VCC IOL < 10 μA  
VOLL  
VOH  
V
V
IOLL = 5 mA  
2.4  
90  
4
IOH = 40 μA  
VOH  
% VCC IOH < 10 μA  
IOHL = -5 mA  
VOHL  
V
1.  
2.  
Not applicable to IRB signals. IRB electrical characteristics are specified in Table 25.  
Typical values are at 25° C and are for design aid only; they are not guaranteed and not subject to  
production testing.  
3.  
Supply current may vary depending on the transformer, LED, and resistor selections.  
Datasheet  
31-Oct-2005  
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Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 22.  
I/O Electrical Characteristics1 (Sheet 2 of 2)  
Parameter  
Input Low current  
Symbol  
Min  
Typ2  
Max  
Units  
Test Conditions  
VOL = .4 V  
IIL  
3
2
8
mA  
ns  
Output rise / fall time  
RESET pulse width  
CLOAD = 20 pF  
PWRESE  
T
1.0  
ms  
VCC = 4.75 V  
RESET fall time  
TFRESET  
20.0  
μs  
VIHRESET to VILRESET  
NOTES:  
1.  
2.  
Not applicable to IRB signals. IRB electrical characteristics are specified in Table 25.  
Typical values are at 25° C and are for design aid only; they are not guaranteed and not subject to  
production testing.  
3.  
Supply current may vary depending on the transformer, LED, and resistor selections.  
Table 23.  
AUI Electrical Characteristics  
Parameter  
Input Low current  
Symbol  
Min  
Typ1  
Max  
Units  
Test Conditions  
IIL  
IIH  
-700  
500  
μA  
μA  
mV  
Input High current  
Differential output voltage  
VOD  
±550  
±1200  
Between CIP/CIN & DIP/  
DIN  
Receive input impedance  
ZIN  
20  
kΩ  
Differential squelch threshold  
VDS  
220  
mV  
Note:  
1.  
Typical values are at 25° C and are for design aid only; they are not guaranteed and not subject to  
production testing.  
Table 24.  
Twisted-Pair Electrical Characteristics  
Parameter  
Symbol  
Min  
Typ1  
Max  
Units  
Test Conditions  
Transmit output impedance  
ZOUT  
5
Ω
Load = 100 Ω at TPOP  
Peak differential output voltage  
Transmit timing jitter addition  
VOD  
3.3  
3.5  
3.7  
V
and TPON  
± 6.4  
± 10  
ns  
0 line length  
After line model specified  
by IEEE 802.3 for  
10BASE-T  
Transmit timing jitter added by  
the MAU and PLS sections2  
± 3.5  
± 5.5  
ns  
Receive input impedance  
ZIN  
20  
kΩ  
Between TPIP/TPIN  
Differential squelch threshold  
(Normal threshold: ERSQx = 0)  
VDS  
300  
420  
565  
mV  
5 MHz square wave input  
Differential squelch threshold  
(Reduced threshold: ERSQx = 1)  
VDSL  
180  
250  
345  
mV  
5 MHz square wave input  
NOTES:  
1.  
Typical values are at 25° C and are for design aid only; they are not guaranteed and not subject to  
production testing.  
2.  
IEEE 802.3 specifies maximum jitter additions at 1.5 ns for the AUI cable, 0.5 ns from the encoder,  
and 3.5 ns from the MAU.  
31-Oct-2005  
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Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Table 25.  
IRB Electrical Characteristics  
Parameter  
Symbol  
Min  
Typ1  
Max  
Units  
Test Conditions  
Output Low voltage  
VOL  
TF  
.3  
4
.6  
V
Output rise or fall time  
12  
ns  
Input Low voltage: IRENA,  
IRCOL & IRDAT  
VILIRB  
VIHIRB  
0.8  
V
V
RL = 330 Ω  
Input High voltage: IRENA,  
IRCOL & IRDAT  
3.0  
RL = 330 Ω  
Input Low voltage: BCLKIO  
Input High voltage: BCLKIO  
Note:  
VILBCLK  
VIHBCLK  
0.4  
V
V
RL = 330 Ω  
RL = 330 Ω  
4.0  
1.  
Typical values are at 25° C and are for design aid only; they are not guaranteed and not subject to  
production testing.  
Table 26.  
Switching Characteristics  
Parameter  
Min  
Typ1 Max Units  
Maximum transmit time  
Unjab time  
5.0  
9.6  
60  
5.5  
ms  
μs  
Jabber Timing  
Time link loss  
ms  
ms  
ms  
Link Integrity Timing Time between Link Integrity Pulses  
Interval for valid receive Link Integrity Pulses  
Note:  
10  
4.1  
20  
30  
1.  
Typical values are at 25° C and are for design aid only; they are not guaranteed and not subject to  
production testing.  
Table 27.  
Serial Port Timing—External Mode  
Parameter  
Symbol  
Minimum  
Typical1 Maximum  
Units  
SCLKIO High to SENI Low (active)  
SCLKIO High to SDIN data valid  
SCLKIO High to SENO Low (active)  
SCLKIO Low to SDOUT data valid  
Note:  
tS1  
tS2  
tS3  
tS4  
0
0
5
5
50  
50  
15  
15  
ns  
ns  
ns  
ns  
1.  
Typical values are at 25° C and are for design aid only; they are not guaranteed and not subject to  
production testing.  
Datasheet  
31-Oct-2005  
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Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 12.  
Serial Port Timing  
SCLKIO  
RESET  
t
t
S1  
SENI  
S2  
SDIN  
tS3  
SENO  
tS4  
1
2
3
4
5
6
48  
SDOUT  
Table 28.  
Inter-Repeater Bus Timing  
Parameter  
Symbol  
Minimum  
Typical1 Maximum  
Units  
Start of Frame to IRDEN Low (active)  
Start of Frame to IRENA Low (active)  
tIRB1  
tIRB2  
tIRB3  
tIRB3  
tIRB4  
tIRB5  
tIRB6  
10  
125  
5
150  
225  
30  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
BCLKIO to IRDAT valid (Synchronous mode)  
BCLKIO to IRDAT valid (Asynchronous mode)  
IRENA Low (active) to TP outputs active  
IRENA Low (active) to AUI output active  
End of Frame clock to IRENA High (inactive)  
50  
525  
475  
5
600  
525  
30  
IRENA High (inactive) to IRDEN High  
(inactive)  
tIRB7  
95  
105  
ns  
IRENA High (inactive) to TP outputs inactive  
IRENA High (inactive) to AUI output inactive  
Note:  
tIRB8  
tIRB9  
575  
425  
600  
450  
ns  
ns  
1.  
Typical values are at 25° C and are for design aid only; they are not guaranteed and not subject to  
production testing.  
31-Oct-2005  
38  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 13.  
Inter-Repeater Bus Timing  
Rx DATA  
t
IRB4  
t
IRB8  
TPs  
AUI  
t
IRB5  
t
IRB9  
t
IRB7  
t
IRB1  
IRDEN  
tIRB6  
tIRB2  
IRENA  
IRDAT  
tIRB3  
BCLKIO  
Datasheet  
31-Oct-2005  
39  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
5.0  
Package Specifications  
Figure 14.  
LXT914PC/PE Package Specifications  
68-Pin Plastic Leaded Chip Carrier  
Part Number LXT914PC for Commercial Temperature Range (0°C to +70°C)  
Part Number LXT914PE for Extended Temperature Range (-40°C to +85°C)  
Millimet  
Dim  
Inches  
ers  
Min  
Max  
Min  
Max  
A
0.165  
0.090  
0.062  
0.050  
0.026  
0.985  
0.950  
0.013  
0.180  
0.120  
0.083  
4.191  
2.286  
1.575  
1.270  
0.660  
25.019  
24.130  
0.330  
4.572  
3.048  
2.108  
A1  
A2  
B
C
0.032  
0.995  
0.958  
0.021  
0.813  
25.273  
24.333  
0.533  
D
D1  
F
31-Oct-2005  
40  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 15.  
LXT914QC Package Specifications  
100-Pin Quad Flat Package  
Part Number LXT914QC  
Commercial Temperature Range (0 C to +70 C)  
°
°
Dim  
Inches  
Millimeters  
Max  
Min  
Max  
0.134  
Min  
A
3.40  
A1  
0.010  
0.100  
0.009  
0.931  
0.783  
0.25  
A2  
B
0.120 2.55  
0.015 0.22  
0.951 23.65  
0.791 19.90  
3.05  
0.38  
24.15  
20.10  
D
D1  
D3  
E
0.742 REF  
0.695  
18.85 REF  
D Side pin count = 30  
ESide pin count =20  
0.715 17.65  
0.555 13.90  
18.15  
14.10  
E1  
E3  
0.547  
0.486 REF  
12.35 REF  
(nominal)  
(nominal)  
e
0.026 BSC1  
0.65 BSC1  
L
0.026  
0.077 ref  
0°  
0.037 0.65  
0.95  
L1  
q
1.95 ref  
7°  
0°  
5°  
7°  
q3  
1.  
5°  
16°  
16°  
BSC = Basic Spacing Between Centers  
Datasheet  
31-Oct-2005  
41  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
5.1  
Top-Label Marking  
Figure 16 shows a sample PLCC package for the LXT914 Repeater.  
Note:  
In contrast to the Pb-Free (RoHS-compliant) PLCC packages, the non-RoHS-compliant packages  
do not have the “e3” symbol in the last line of the package label.  
Figure 16.  
Sample PLCC Package - Intel® LXT914 Repeater  
Pin1  
Part Number  
LXT914PC B3  
FPO Number  
XXXXXXXX  
BSMC  
Bottom Side Mark Code  
B5388-01  
Figure 17 shows a sample Pb-Free (RoHS-compliant) PLCC package for the LXT914 Repeater.  
Figure 17.  
Sample Pb-Free (RoHS-Compliant) PLCC Package - Intel® LXT914 Repeater  
Pin1  
Part Number  
EELXT914C B3  
FPO Number  
XXXXXXXX  
BSMC  
Pb-Free Indication  
e3  
Bottom Side Mark Code  
B5389-01  
31-Oct-2005  
42  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 18 shows a sample PQFP package for the LXT914 Repeater.  
Note:  
In contrast to the Pb-Free (RoHS-compliant) PQFP packages, the non-RoHS-compliant packages  
do not have the “e3” symbol in the last line of the package label.  
Figure 18.  
Sample PQFP Package - Intel® LXT914 Repeater  
Pin 1  
Part Number  
LXT914QC B3  
FPO Number  
XXXXXXXX  
BSMC  
Bottom Side Mark Code  
B5390-01  
Figure 19 shows a sample Pb-Free (RoHS-compliant) PQFP package for the LXT914 Repeater.  
Figure 19.  
Sample Pb-Free (RoHS-Compliant) PQFP Package - Intel® LXT914 Repeater  
Pin 1  
Part Number  
EGLXT914C B3  
FPO Number  
XXXXXXXX  
BSMC  
Pb-Free Indication  
e3  
Bottom Side Mark Code  
B5391-01  
Datasheet  
31-Oct-2005  
43  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
6.0  
Product Ordering Information  
Figure 29 and Figure 20 provide IXF1110 MAC product ordering information.  
Table 29.  
Product Ordering Information  
RoHS  
Compliant  
Number  
Revision  
Package Type  
Pin Count  
NLXT914PC.B3  
EELXT914PC.B3  
NLXT914PE.B3  
EELXT914PE.B3  
SLXT914QC.B3  
EGLXT914QC.B3  
B3  
B3  
B3  
B3  
B3  
B3  
PLCC  
PLCC  
PLCC  
PLCC  
PQFP  
PQFP  
68  
68  
No  
Yes  
No  
68  
68  
Yes  
No  
100  
100  
Yes  
31-Oct-2005  
44  
Datasheet  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Figure 20.  
Ordering Information Matrix – Sample  
N
LXT  
914  
P
C
B3  
Product Revision  
xn = 2 Alphanumeric characters  
Temperature Range  
A = Ambient (0 – 550 C)  
C = Commercial (0 – 700 C)  
E = Extended (-40 – 850 C)  
Internal Package Designator  
L = LQFP  
P = PLCC  
N = DIP  
Q = PQFP  
H = QFP  
T = TQFP  
B = BGA  
C = CBGA  
E = TBGA  
K = HSBGA (BGA with heat slug  
Product Code  
xxxxx = 3-5 Digit alphanumeric  
IXA Product Prefix  
LXT = PHY layer device  
IXE = Switching engine  
IXF = Formatting device (MAC/Framer)  
IXP = Network processor  
Intel Package Designator  
B5360-01  
§ §  
Datasheet  
31-Oct-2005  
Intel® LXT914 Flexible Quad Ethernet Repeater  
Order Number: 248989, Revision: 003  
45  

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