CS8406-IZ [CIRRUS]

192 KHZ DIGITAL AUDIO INTERFACE TRANSMITTER; 192千赫数字音频接口发射器
CS8406-IZ
型号: CS8406-IZ
厂家: CIRRUS LOGIC    CIRRUS LOGIC
描述:

192 KHZ DIGITAL AUDIO INTERFACE TRANSMITTER
192千赫数字音频接口发射器

文件: 总43页 (文件大小:632K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
CS8406  
192 kHz Digital Audio Interface Transmitter  
Features  
General Description  
The CS8406 is a monolithic CMOS device which en-  
codes and transmits audio data according to the AES3,  
IEC60958, S/PDIF, or EIAJ CP1201. The CS8406 ac-  
cepts audio and digital data, which is then multiplexed,  
encoded and driven onto a cable.  
Complete EIAJ CP1201, IEC-60958, AES3,  
S/PDIF compatible transmitter  
+3.3 V or 5.0 V Digital Supply (VD)  
+3.3 V or 5.0 V Digital Interface (VL)  
On-chip Channel Status and User bit buffer  
memories allow block sized updates  
Flexible 3-wire serial digital audio input port  
Up to 192 kHz frame rate  
Microcontroller write access to Channel  
Status and User bit data  
On-chip differential line driver  
Generates CRC codes and parity bits  
Standalone mode allows use without a  
microcontroller  
The audio data is input through a configurable, 3-wire  
input port. The channel status and user bit data are input  
through an SPI or I²C microcontroller port, and may be  
assembled in block sized buffers. For systems with no  
microcontroller, a stand alone mode allows direct ac-  
cess to channel status and user bit data pins.  
Target applications include A/V Receivers, CD-R, DVD  
receivers, digital mixing consoles, effects processors,  
set-top boxes, and computer and automotive audio  
systems.  
ORDERING INFORMATION  
28-pin SOIC/TSSOP package  
CS8406-CS 28-pin SOIC  
-10 to +70°C  
CS8406-CZ 28-pin TSSOP -10 to +70°C  
CS8406-IS  
CS8406-IZ  
CS8406-DS 28-pin SOIC  
28-pin SOIC  
28-pin TSSOP -40 to +85°C  
-40 to +85°C  
CS8406-DZ 28-pin TSSOP -40 to +85°C  
CDB8416 Evaluation Board  
-40 to +85°C  
I
GND  
VL  
VD  
RXP  
TXP  
C & U bit  
AES3  
Data  
Buffer  
S/PDIF  
Encoder  
Driver  
TXN  
TCBL  
ILRCK  
ISCLK  
SDIN  
Serial  
Audio  
Input  
Control  
Port &  
Registers  
Output  
Clock  
Generator  
Misc.  
Control  
H/S RST  
U
SDA/  
SCL/ AD1/ AD0/ AD2 INT  
OMCK  
CDOUT CCLK CDIN CS  
Copyright Cirrus Logic, Inc. 2004  
(All Rights Reserved)  
JUL ‘04  
DS580F1  
www.cirrus.com  
1
CS8406  
TABLE OF CONTENTS  
1. CHARACTERISTICS AND SPECIFICATIONS ........................................................................ 5  
SPECIFIED OPERATING CONDITIONS ................................................................................. 5  
ABSOLUTE MAXIMUM RATINGS ........................................................................................... 5  
DC ELECTRICAL CHARACTERISTICS................................................................................... 6  
DIGITAL INPUT CHARACTERISTICS ..................................................................................... 6  
DIGITAL INTERFACE SPECIFICATIONS................................................................................ 6  
TRANSMITTER CHARACTERISTICS ..................................................................................... 6  
SWITCHING CHARACTERISTICS .......................................................................................... 7  
SWITCHING CHARACTERISTICS - SERIAL AUDIO PORTS................................................. 7  
SWITCHING CHARACTERISTICS - CONTROL PORT - SPI MODE...................................... 9  
SWITCHING CHARACTERISTICS - CONTROL PORT - I²C MODE..................................... 10  
2. TYPICAL CONNECTION DIAGRAMS ................................................................................... 11  
3. GENERAL DESCRIPTION ..................................................................................................... 13  
3.1 AES3 and S/PDIF Standards Documents ........................................................................ 13  
4. THREE-WIRE SERIAL INPUT AUDIO PORT ........................................................................ 14  
5. AES3 TRANSMITTER ............................................................................................................ 16  
5.1 Transmitted Frame and Channel Status Boundary Timing .............................................. 16  
5.2 TXN and TXP Drivers ...................................................................................................... 16  
5.3 Mono Mode Operation ..................................................................................................... 17  
6. CONTROL PORT DESCRIPTION .......................................................................................... 19  
6.1. SPI Mode ........................................................................................................................ 19  
6.2. I²C Mode ......................................................................................................................... 20  
6.3. Memory Address Pointer (MAP) ..................................................................................... 21  
6.3.1. Memory Address Pointer (MAP) Register Detail  
........................................... 21  
6.3.2. INCR (Auto Map Increment Enable) .................................................................. 21  
6.3.3. MAP6-0 (Memory Address Pointer) ................................................................... 21  
7. CONTROL PORT REGISTER SUMMARY ............................................................................. 22  
8. CONTROL PORT REGISTER BIT DEFINITIONS .................................................................. 23  
8.1 Control 1 (01h).................................................................................................................. 23  
8.2 Control 2 (02h).................................................................................................................. 24  
8.3 Data Flow Control (03h).................................................................................................... 24  
8.4 Clock Source Control (04h)............................................................................................... 25  
8.5 Serial Audio Input Port Data Format (05h)........................................................................ 25  
8.6 Interrupt 1 Status (07h) (Read Only)................................................................................. 26  
8.7 Interrupt 2 Status (08h) (Read Only)................................................................................. 27  
8.8 Interrupt 1 Mask (09h)....................................................................................................... 27  
8.9 Interrupt 1 Mode MSB (0Ah) and Interrupt 1 Mode LSB (0Bh)......................................... 27  
8.10 Interrupt 2 Mask (0Ch).................................................................................................... 27  
8.11 Interrupt 2 Mode MSB (0Dh) and Interrupt Mode 2 LSB (0Eh)....................................... 28  
8.12 Channel Status Data Buffer Control (12h) ...................................................................... 28  
8.13 User Data Buffer Control (13h) ....................................................................................... 29  
8.14 Channel Status bit or User bit Data Buffer (20h - 37h) ................................................... 29  
8.15 CS8406 I.D. and Version Register (7Fh) (Read Only).................................................... 29  
9. PIN DESCRIPTION - SOFTWARE MODE .......................................................................... 30  
10. HARDWARE MODE ............................................................................................................. 32  
10.1 Channel Status, User and Validity Data ......................................................................... 32  
10.2 Serial Audio Port ............................................................................................................ 33  
11. PIN DESCRIPTION - HARDWARE MODE .......................................................................... 34  
12. APPLICATIONS .................................................................................................................... 36  
12.1 Reset, Power Down and Start-up .................................................................................. 36  
12.2 ID Code and Revision Code .......................................................................................... 36  
2
DS580F1  
CS8406  
12.3 Power Supply, Grounding, and PCB layout ................................................................... 36  
12.4 Synchronization of Multiple CS8406s ............................................................................ 36  
13. PACKAGE DIMENSIONS .................................................................................................. 37  
14. APPENDIX A: EXTERNAL AES3/SPDIF/IEC60958 TRANSMITTER COMPONENTS ...... 39  
14.1 AES3 Transmitter External Components ....................................................................... 39  
14.2 Isolating Transformer Requirements ............................................................................. 39  
15. APPENDIX B: CHANNEL STATUS AND USER DATA BUFFER MANAGEMENT ........... 40  
15.1 AES3 Channel Status(C) Bit Management .................................................................... 40  
15.1.1 Accessing the E buffer ...................................................................................... 40  
15.1.2 Serial Copy Management System (SCMS) ....................................................... 41  
15.1.3 Channel Status Data E Buffer Access .............................................................. 41  
15.2 AES3 User (U) Bit Management .................................................................................... 42  
15.2.1 Mode 1: Transmit All Zeros ............................................................................... 42  
15.2.2 Mode 2: Block Mode ......................................................................................... 42  
16. REVISION HISTORY ............................................................................................................ 43  
DS580F1  
3
CS8406  
LIST OF FIGURES  
Figure 1. Audio Port Master Mode Timing....................................................................................... 8  
Figure 2. Audio Port Slave Mode and Data Input Timing................................................................ 8  
Figure 3. SPI Mode timing............................................................................................................... 9  
Figure 4. I²C Mode timing.............................................................................................................. 10  
Figure 5. Recommended Connection Diagram for Software Mode............................................... 11  
Figure 6. Recommended Connection Diagram for Hardware Mode ............................................. 12  
Figure 7. Serial Audio Input Example Formats.............................................................................. 15  
Figure 8. AES3 Transmitter Timing for C, U, and V Pin Input Data .............................................. 18  
Figure 9. Control Port Timing in SPI Mode.................................................................................... 19  
Figure 10. Control Port Timing, I²C Slave Mode Write .................................................................. 20  
Figure 11. Control Port Timing, I²C Slave Mode Read.................................................................. 20  
Figure 12. Hardware Mode Data Flow .......................................................................................... 32  
Figure 13. Professional Output Circuit .......................................................................................... 39  
Figure 14. Consumer Output Circuit (VL = 5.0 V) ......................................................................... 39  
Figure 15. TTL/CMOS Output Circuit............................................................................................ 39  
Figure 16. Channel Status Data Buffer Structure.......................................................................... 40  
Figure 17. Flowchart for Writing the E Buffer ................................................................................ 41  
LIST OF TABLES  
Table 1. Control Register Map Summary...................................................................................... 22  
Table 2. Hardware Mode COPY/C and ORIG pin functions.......................................................... 33  
Table 3. Hardware Mode Serial Audio Port Format Selection....................................................... 33  
Table 4. Hardware Mode OMCK Clock Ratio Selection................................................................ 33  
Table 5. Equivalent Register Settings of Serial Audio Input Formats  
Available in Hardware Mode ............................................................................... 33  
Table 6. Revision History .............................................................................................................. 43  
4
DS580F1  
CS8406  
1. CHARACTERISTICS AND SPECIFICATIONS  
(All Min/Max characteristics and specifications are guaranteed over the Specified Operating Conditions. Typical per-  
formance characteristics and specifications are derived from measurements taken at nominal supply voltages and  
T = 25°C.)  
A
SPECIFIED OPERATING CONDITIONS (GND = 0 V, all voltages with respect to 0 V)  
Parameter  
Symbol  
Min  
Typ  
Max  
Units  
Power Supply Voltage  
VD  
VL  
3.14  
3.14  
3.3 or 5.0  
3.3 or 5.0  
5.25  
5.25  
V
V
Ambient Operating Temperature:  
‘-CS’ & ‘-CZ’  
‘-IS’, ‘-IZ’, ‘-DS’, & ‘-DZ’  
T
-10  
-40  
-
-
+70  
+85  
°C  
°C  
A
T
A
ABSOLUTE MAXIMUM RATINGS (GND = 0 V; all voltages with respect to 0 V. Operation beyond  
these limits may result in permanent damage to the device. Normal operation is not guaranteed at these extremes.)  
Parameter  
Symbol  
Min  
-
Max  
6.0  
Units  
V
Power Supply Voltage  
VD, VL  
Input Current, Any Pin Except Supplies  
Input Voltage  
(Note 1)  
I
-
10  
mA  
V
in  
V
-0.3  
-55  
-65  
VL + 0.3  
125  
in  
Ambient Operating Temperature (power applied)  
Storage Temperature  
T
°C  
A
T
150  
°C  
stg  
Notes: 1. Transient currents of up to 100 mA will not cause SCR latch-up.  
DS580F1  
5
CS8406  
DC ELECTRICAL CHARACTERISTICS (GND = 0 V; all voltages with respect to 0 V.)  
Parameters  
Symbol  
Min  
Typ  
Max  
Units  
Power-down Mode (Note 2)  
Supply Current in power down  
VD = 3.3 V  
VD = 5.0 V  
VL = 3.3 V  
VL = 5.0 V  
ID  
ID  
IL  
-
-
-
-
20  
40  
0
-
-
-
-
µA  
µA  
µA  
µA  
IL  
0
Normal Operation (Note 3)  
Supply Current at 48 kHz frame rate (Note 4)  
VD = 3.3 V  
VD = 5.0 V  
VL = 3.3 V  
VL = 5.0 V  
ID  
ID  
IL  
-
-
-
-
1.9  
3.5  
6.5  
-
-
-
-
mA  
mA  
mA  
mA  
IL  
10.6  
Supply Current at 192 kHz frame rate (Note 4)  
VD = 3.3 V  
VD = 5.0 V  
VL = 3.3 V  
VL = 5.0 V  
ID  
ID  
IL  
-
-
-
-
7.6  
12.7  
7.2  
12  
-
-
-
-
mA  
mA  
mA  
mA  
IL  
Notes: 2. Power Down Mode is defined as RST = LO with all clocks and data lines held static.  
3. Normal operation is defined as RST = HI.  
4. Assumes that no inputs are left floating. It is recommended that all digital inputs be driven high or low  
at all times.  
DIGITAL INPUT CHARACTERISTICS  
Parameters  
Symbol  
Min  
Typ  
-
Max  
0.5  
-
Units  
µA  
V
Input Leakage Current  
Input Hysteresis (all inputs except OMCK)  
I
-
-
in  
0.25  
DIGITAL INTERFACE SPECIFICATIONS (GND = 0 V; all voltages with respect to 0 V.)  
Parameters  
Symbol  
Min  
Max  
Units  
High-Level Output Voltage (I  
= -3.2 mA), except TXP/TXN  
V
VL - 1.0  
-
V
OH  
OH  
Low-Level Output Voltage (I  
= 3.2 mA), except TXP/TXN  
V
-
0.4  
V
OH  
OL  
High-Level Output Voltage, TXP, TXN  
Low-Level Output Voltage, TXP, TXN  
High-Level Input Voltage  
(21 mA at VL = 5.0 V)  
(15 mA at VL = 3.3 V)  
VL - 0.7  
VL - 0.7  
VL  
VL  
V
V
(21 mA at VL = 5.0 V)  
(16 mA at VL = 3.3 V)  
-
-
0.7  
0.7  
V
V
VD = 5.0 V  
VD = 3.3 V  
V
2.75  
2.0  
VL + 0.3  
VL + 0.3  
V
V
IH  
Low-Level Input Voltage  
VD = 5.0 V  
VD = 3.3 V  
V
-0.3  
-0.3  
0.8  
0.8  
V
V
IL  
TRANSMITTER CHARACTERISTICS  
Parameters  
Symbol  
Typ  
Units  
TXP Output Resistance  
VL = 5.0 V  
VL = 3.3 V  
R
26.5  
33.5  
TXP  
TXN Output Resistance  
VL = 5.0 V  
VL = 3.3 V  
R
26.5  
33.5  
TXN  
6
DS580F1  
CS8406  
SWITCHING CHARACTERISTICS  
(Inputs: Logic 0 = 0 V, Logic 1 = VL; C = 20 pF)  
L
Parameter  
RST pin Low Pulse Width  
Symbol  
Min  
200  
4.1  
4.1  
3.1  
6.1  
2.0  
8.1  
1.0  
18.3  
8
Typ  
Max  
Units  
µs  
MHz  
ns  
-
-
OMCK Frequency for OMCK = 512*Fs  
OMCK Low and High Width for OMCK = 512*Fs  
OMCK Frequency for OMCK = 384*Fs  
OMCK Low and High Width for OMCK = 384*Fs  
OMCK Frequency for OMCK = 256*Fs  
OMCK Low and High Width for OMCK = 256*Fs  
OMCK Frequency for OMCK = 128*Fs  
OMCK Low and High Width for OMCK = 128*Fs  
Frame Rate  
-
98.4  
-
-
-
73.8  
MHz  
ns  
-
-
49.2  
-
-
MHz  
ns  
-
-
24.6  
-
MHz  
ns  
-
-
192  
-
kHz  
ps  
AES3 Transmitter Output Jitter  
-
200  
SWITCHING CHARACTERISTICS - SERIAL AUDIO PORTS  
(Inputs: Logic 0 = 0 V, Logic 1 = VL; C = 20 pF)  
L
Parameter  
SDIN Setup Time Before ISCLK Active Edge  
SDIN Hold Time After ISCLK Active Edge  
Master Mode  
Symbol  
Min  
10  
8
Typ  
Max  
Units  
ns  
(Note 5)  
(Note 5)  
t
t
-
-
-
-
ds  
dh  
ns  
OMCK to ISCLK active edge delay  
OMCK to ILRCK delay  
(Note 5)  
(Note 6)  
t
0
0
-
-
-
17  
16  
-
ns  
ns  
%
smd  
t
lmd  
ISCLK and ILRCK Duty Cycle  
Slave Mode  
50  
ISCLK Period  
t
36  
14.4  
14.4  
10  
-
-
-
-
-
-
-
-
-
-
ns  
ns  
ns  
ns  
ns  
sckw  
ISCLK Input Low Width  
t
sckl  
sckh  
lrckd  
lrcks  
ISCLK Input High Width  
t
ISCLK Active Edge to ILRCK Edge  
ILRCK Edge Setup Before ISCLK Active Edge  
(Note 7)  
(Note 8)  
t
t
10  
Notes: 5. The active edge of ISCLK is programmable in Software mode.  
6. The polarity of ILRCK is programmable in Software mode.  
7. Prevents the previous ISCLK edge from being interpreted as the first one after ILRCK has changed.  
8. This setup time ensures that this ISCLK edge is interpreted as the first one after ILRCK has changed.  
DS580F1  
7
CS8406  
ILRCK  
(input)  
ISCLK  
(output)  
t
t
t
t
lrckd  
lrcks  
sckh  
sckl  
ISCLK  
(input)  
ILRCK  
(output)  
t
sckw  
t
smd  
t
lmd  
SDIN  
OMCK  
(input)  
t
t
ds  
dh  
Figure 1. Audio Port Master Mode Timing  
Figure 2. Audio Port Slave Mode and Data Input  
Timing  
8
DS580F1  
CS8406  
SWITCHING CHARACTERISTICS - CONTROL PORT - SPI MODE  
(Inputs: Logic 0 = 0 V, Logic 1 = VL; C = 20 pF)  
L
Parameter  
CCLK Clock Frequency  
Symbol  
Min  
0
Typ  
Max  
Units  
MHz  
µs  
(Note 9)  
f
t
-
-
-
-
6.0  
sck  
CS High Time Between Transmissions  
CS Falling to CCLK Edge  
CCLK Low Time  
1.0  
20  
66  
-
-
-
csh  
t
ns  
css  
t
ns  
scl  
CCLK High Time  
(Note 10)  
(Note 11)  
t
MAX ((1/256 F + 8), 66)  
ns  
sch  
S
CDIN to CCLK Rising Setup Time  
CCLK Rising to DATA Hold Time  
CCLK Falling to CDOUT Stable  
Rise Time of CDOUT  
t
40  
15  
-
-
-
-
-
-
-
-
-
ns  
dsu  
t
t
-
ns  
dh  
pd  
50  
25  
25  
100  
100  
ns  
t
-
ns  
r1  
Fall Time of CDOUT  
t
-
ns  
f1  
Rise Time of CCLK and CDIN  
Fall Time of CCLK and CDIN  
(Note 12)  
(Note 12)  
t
-
ns  
r2  
t
-
ns  
f2  
Notes: 9. If Fs is lower than 51.850 kHz, the maximum CCLK frequency should be less than 115 Fs. This is  
dictated by the timing requirements necessary to access the Channel Status and User Bit buffer  
memory. Access to the control register file can be carried out at the full 6 MHz rate.  
10. T  
must be greater than the larger of the two values, either 1/256FS + 8 ns, or 66 ns.  
sch  
11. Data must be held for sufficient time to bridge the transition time of CCLK.  
12. For f  
< 1 MHz.  
sck  
CS  
t
t
scl  
sch  
t
t
csh  
css  
CCLK  
t
t
r2  
f2  
CDIN  
t
dsu  
t
dh  
t
pd  
CDOUT  
Figure 3. SPI Mode timing  
DS580F1  
9
CS8406  
SWITCHING CHARACTERISTICS - CONTROL PORT - I²C MODE  
(Inputs: Logic 0 = 0 V, Logic 1 = VL; C = 20 pF)  
L
Parameter  
SCL Clock Frequency  
Symbol  
Min  
-
Typ  
Max  
Units  
kHz  
µs  
µs  
µs  
µs  
µs  
µs  
ns  
f
t
-
-
-
-
-
-
-
-
-
-
-
100  
scl  
Bus Free Time Between Transmissions  
Start Condition Hold Time (prior to first clock pulse)  
Clock Low Time  
4.7  
4.0  
4.7  
4.0  
4.7  
0
-
buf  
t
-
hdst  
t
-
low  
high  
sust  
Clock High Time  
t
t
-
Setup Time for Repeated Start Condition  
SDA Hold Time from SCL Falling  
SDA Setup Time to SCL Rising  
Rise Time of Both SDA and SCL Lines  
Fall Time of Both SDA and SCL Lines  
Setup Time for Stop Condition  
-
(Note 13)  
t
-
-
hdd  
sud  
t
250  
-
t
t
1000  
300  
-
ns  
r
f
-
ns  
t
4.7  
µs  
susp  
13. Data must be held for sufficient time to bridge the 300 ns transition time of SCL.  
Repeated  
Stop  
t
Start  
Stop  
Start  
SDA  
SCL  
t
t
t
t
buf  
t
high  
hdst  
f
susp  
hdst  
t
t
t
t
t
sust  
sud  
r
low  
hdd  
Figure 4. I²C Mode timing  
10  
DS580F1  
CS8406  
2. TYPICAL CONNECTION DIAGRAMS  
+3.3 V or +5.0 V  
+3.3 V or +5.0 V  
0.1µF  
0.1µF  
VD  
VL  
AES3 /  
S/PDIF  
Source  
RXP  
ILRCK  
ISCLK  
SDIN  
TXP  
TXN  
Transmission  
Serial  
Audio  
Source  
Interface  
CS8406  
Clock Source  
and Control  
OMCK  
User Data  
Source  
U
AD0 / CS  
AD1 / CDIN  
AD2  
47kΩ  
SCL / CCLK  
SDA / CDOUT  
Microcontroller  
H/S  
RST  
INT  
TCBL  
GND  
To/from other  
CS8406's  
Figure 5. Recommended Connection Diagram for Software Mode  
DS580F1  
11  
CS8406  
+3.3 V or +5.0 V  
0.1µF  
+3.3 V or +5.0 V  
0.1µF  
VD  
VL  
H/S  
ILRCK  
ISCLK  
SDIN  
Serial  
Audio  
Source  
TXP  
TXN  
Transmission  
Interface  
CS8406  
Clock Source  
and Control  
OMCK  
C Data  
Source  
COPY/C  
U
HWCK1  
HWCK0  
SFMT0  
SFMT1  
APMS  
User Data  
Source  
47kΩ  
47kΩ  
TCBLD  
Hardware  
Control  
RST  
CEN  
EMPH  
Validity  
Source  
V
AUDIO  
ORIG  
TCBL  
GND  
To/from other  
CS8406's  
Figure 6. Recommended Connection Diagram for Hardware Mode  
12  
DS580F1  
CS8406  
3. GENERAL DESCRIPTION  
The CS8406 is a monolithic CMOS device which encodes and transmits audio data according to  
the AES3, IEC60958, S/PDIF, and EIAJ CP1201 interface standards. The CS8406 accepts au-  
dio, channel status and user data, which is then multiplexed, encoded, and driven onto a cable.  
The audio data is input through a configurable, 3-wire input port. The channel status bits and user  
bit data are input through an SPI or I²C Mode microcontroller port and may be assembled in sep-  
arate block sized buffers.  
For systems with no microcontroller, a stand alone mode allows direct access to channel status  
and user data input pins.  
Target applications include CD-R, DAT, DVD, MD and VTR equipment, mixing consoles, digital  
audio transmission equipment, high quality A/D converters, effects processors, set-top TV box-  
es, and computer audio systems.  
Figure 5 shows the supply and external connections to the CS8406 when configured for opera-  
tion with a microcontroller. Figure 6 shows the supply and external connections to the CS8406  
when configured for operation without a microcontroller.  
3.1 AES3 and S/PDIF Standards Documents  
This data sheet assumes that the user is familiar with the AES3 and S/PDIF data formats. It is  
advisable to have current copies of the AES3 and IEC60958 specifications on hand for easy ref-  
erence.  
The latest AES3 standard is available from the Audio Engineering Society or ANSI at  
www.aes.org or www.ansi.org. Obtain the latest IEC60958 standard from ANSI or from the Inter-  
national Electrotechnical Commission at www.iec.ch. The latest EIAJ CP-1201 standard is avail-  
able from the Japanese Electronics Bureau.  
Application Note 22: Overview of Digital Audio Interface Data Structures contains a useful tutorial  
on digital audio specifications, but it should not be considered a substitute for the standards.  
The paper An Understanding and Implementation of the SCMS Serial Copy Management Sys-  
tem for Digital Audio Transmission, by Clifton Sanchez, is an excellent tutorial on SCMS. It is  
available from the AES as reprint 3518.  
DS580F1  
13  
CS8406  
4. THREE-WIRE SERIAL INPUT AUDIO PORT  
A 3-wire serial audio input port is provided. The interface format can be adjusted to suit the at-  
tached device through the control registers. The following parameters are adjustable:  
• Master or slave  
• Serial clock frequency  
• Audio data resolution  
• Left or right justification of the data relative to left/right clock  
• Optional one-bit cell delay of the first data bit  
• Polarity of the bit clock  
• Polarity of the left/right clock. (By setting the appropriate control bits, many formats are pos-  
sible).  
Figure 7 shows a selection of common input formats with the corresponding control bit settings.  
In master mode, the left/right clock and the serial bit clock are outputs, derived from the OMCK  
input pin master clock.  
In slave mode, the left/right clock and the serial bit clock are inputs. The left/right clock must be  
synchronous to the OMCK master clock, but the serial bit clock can be asynchronous and dis-  
continuous if required. The left/right clock should be continuous, but the duty cycle can be less  
than the specified typical value of 50% if enough serial clocks are present in each phase to clock  
all the data bits.  
14  
DS580F1  
CS8406  
Right  
Left  
ILRCK  
ISCLK  
SDIN  
Left  
Justified  
(In)  
MSB  
LSB  
MSB  
LSB  
MSB  
Left  
Right  
ILRCK  
I2S  
(In)  
ISCLK  
SDIN  
LSB  
MSB  
LSB  
MSB  
MSB  
Right  
MSB  
Left  
ILRCK  
ISCLK  
Right  
Justified  
(In)  
LSB  
MSB  
LSB  
LSB  
SDIN  
SIMS*  
SISF*  
SIRES[1:0]* SIJUST*  
SIDEL*  
SISPOL* SILRPOL*  
Left Justified  
I²S  
X
X
X
X
X
X
00+  
00+  
XX  
0
0
1
0
1
0
0
0
0
0
1
0
Right Justified  
X = don’t care to match format, but does need to be set to the desired setting  
+ I²S can accept an arbitrary number of bits, determined by the number of ISCLK cycles  
* See Serial Input Port Data Format Register Bit Descriptions for an explanation of the meaning of each bit  
Figure 7. Serial Audio Input Example Formats  
DS580F1  
15  
CS8406  
5. AES3 TRANSMITTER  
The CS8406 includes an AES3 digital audio transmitter. A comprehensive buffering scheme pro-  
vides write access to the channel status and user data. This buffering scheme is described in  
Appendix B: Channel Status and User Data Buffer Management.  
The AES3 transmitter encodes and transmits audio and digital data according to the AES3,  
IEC60958 (S/PDIF), and EIAJ CP-1201 interface standards. Audio and control data are multi-  
plexed together and bi-phase mark encoded. The resulting bit stream is driven to an output con-  
nector either directly or through a transformer. The transmitter is clocked from the clock input pin,  
OMCK. If OMCK is asynchronous to the data source, an interrupt bit (TSLIP) is provided that will  
go high every time a data sample is dropped or repeated.  
The channel status (C) and user (U) bits in the transmitted data stream are taken from storage  
areas within the CS8406. The user can manually access the internal storage or configure the  
CS8406 to run in one of several automatic modes. Appendix B: Channel Status and User Data  
Buffer Management provides detailed descriptions of each automatic mode and describes meth-  
ods of manually accessing the storage areas. The transmitted user bit data can optionally be in-  
put through the U pin, under the control of a control port register bit.  
Figure 8 shows the C/U/V timing requirements.  
5.1 Transmitted Frame and Channel Status Boundary Timing  
The TCBL pin is used to control or indicate the start of transmitted channel status block bound-  
aries and may be an input or an output.  
In some applications, it may be necessary to control the precise timing of the transmitted AES3  
frame boundaries. This may be achieved in two ways:  
a) With TCBL set to input, driving TCBL high for >3 OMCK clocks will cause a frame start, as well  
as a new channel status block start.  
b) If the serial audio input port is in slave mode and TCBL is set to output, the start of the A chan-  
nel sub-frame will be aligned with the leading edge of ILRCK.  
5.2 TXN and TXP Drivers  
The line drivers are low skew, low impedance, differential outputs capable of driving cables di-  
rectly. Both drivers are set to ground during reset (RST = LOW), when no AES3 transmit clock  
is provided, and optionally under the control of a register bit. The CS8406 also allows immediate  
muting of the AES3 transmitter audio data through a control register bit.  
External components are used to terminate and isolate the external cable from the CS8406.  
These components are detailed in “Appendix A: External AES3/SPDIF/IEC60958 Transmitter  
Components” on page 39.  
16  
DS580F1  
CS8406  
5.3 Mono Mode Operation  
An alternate method for transmitting an AES3 192 kHz sample rate stream is mono mode. Mono  
mode is implemented by using the two sub-frames in a 96 kHz biphase encoded stream to carry  
consecutive samples of a single channel of a 192 kHz PCM stream (i.e. a mono signal). This al-  
lows older equipment, whose AES3 transmitters and receivers are not rated for 192 kHz frame  
rate operation, to handle 192 kHz sample rate information. In this mono mode, two AES3 cables  
and two CS8406's are needed for stereo data transfer. The CS8406 is set to mono mode by the  
MMT control bit.  
In mono mode, the input port will run at the audio sample rate (Fs), while the AES3 transmitter  
frame rate will be at Fs/2. Consecutive left or right channel serial audio data samples may be se-  
lected for transmission on the A and B sub-frames, and the channel status block transmitted is  
also selectable.  
Using mono mode is only necessary if the incoming audio sample rate is already at 192 kHz and  
contains both left and right audio data words. The “mono mode” AES3 output stream may also  
be achieved by keeping the CS8406 in normal stereo mode, and placing consecutive audio sam-  
ples in the left and right positions in an incoming 96 kHz word rate data stream.  
Figure 8 shows the C/U/V timing requirements.  
DS580F1  
17  
CS8406  
Tth  
TCBL  
(In/Output)  
VLRCK  
Tsetup  
Thold  
V/C/U  
(Input)  
VCU[0]  
VCU[1]  
VCU[2]  
VCU[3]  
VCU[4]  
Data [4]  
Data [0]  
Data [5]  
Data [6]  
Data [2]  
Data [7]  
Data [3]  
Data [8]  
Data [4]  
SDIN  
(Input)  
Z
Y
Data [1]  
X
Y
X
TXP(N)  
(Output)  
Tsetup 7.5% AES3 frame time  
Thold = 0  
Tth > 3 OMCK clocks, if TCBL is Input  
AES3 Transmitter in Stereo mode  
TCBL  
(In/Output)  
Tth  
VLRCK  
U
(Input)  
U[0]  
U[2]  
Data [4]  
Data [5]  
Data [6]  
Data [7]  
Data [8]  
SDIN  
(Input)  
Z
Data [0]*  
Y
Y
Data [2]*  
Data [3]*  
X
X
Data [4]*  
Data [5]*  
TXP(N)  
(Output)  
* Assume MMTLR = 0  
TXP(N)  
(Output)  
Z
Data [1]*  
* Assume MMTLR = 1  
Tsetup 15% AES3 frame time  
Thold = 0  
Tth > 3 OMCK clocks, if TCBL is Input  
AES3 Transmitter in Mono mode  
VLRCK is a virtual word clock, which may not exist, and is used to illustrate the CUV timing.  
VLRCK duty cycle is 50%.  
In stereo mode, VLRCK frequency = AES3 frame rate. In mono mode, VLRCK frequency = 2xAES3 frame rate.  
If the serial audio input port is on slave mode and TCBL is an output, then VLRCK = ILRCK if SILRPOL = 0  
and VLRCK = ILRCK if SILRPOL =1.  
If the serial audio input port is in master mode and TCBL is an input, then VLRCK = ILRCK if SILRPOL = 0  
and VLRCK = ILRCK if SILRPOL =1.  
Figure 8. AES3 Transmitter Timing for C, U, and V Pin Input Data  
18  
DS580F1  
CS8406  
6. CONTROL PORT DESCRIPTION  
The control port is used to access the registers, allowing the CS8406 to be configured for the  
desired operational modes and formats. The operation of the control port may be completely  
asynchronous with respect to the audio sample rates. However, to avoid potential interference  
problems, the control port pins should remain static if no operation is required.  
The control port has 2 modes: SPI and I²C, with the CS8406 acting as a slave device. SPI mode  
is selected if there is a high to low transition on the AD0/CS pin, after the RST pin has been  
brought high. I²C mode is selected by connecting the AD0/CS pin through a resistor to VL or  
GND, thereby permanently selecting the desired AD0 bit address state.  
6.1. SPI Mode  
In SPI mode, CS is the CS8406 chip select signal, CCLK is the control port bit clock (input into  
the CS8406 from the microcontroller), CDIN is the input data line from the microcontroller, CD-  
OUT is the output data line to the microcontroller. Data is clocked in on the rising edge of CCLK  
and out on the falling edge.  
Figure 9 shows the operation of the control port in SPI mode. To write to a register, bring CS low.  
The first seven bits on CDIN form the chip address and must be 0010000. The eighth bit is a  
read/write indicator (R/W), which should be low to write. The next eight bits form the Memory Ad-  
dress Pointer (MAP), which is set to the address of the register that is to be updated. The next  
eight bits are the data which will be placed into the register designated by the MAP. During writes,  
the CDOUT output stays in the Hi-Z state. It may be externally pulled high or low with a 47 kΩ  
resistor, if desired.  
There is a MAP auto increment capability, enabled by the INCR bit in the MAP register. If INCR  
is a zero, the MAP will stay constant for successive read or writes. If INCR is set to a 1, the MAP  
will autoincrement after each byte is read or written, allowing block reads or writes of successive  
registers.  
To read a register, the MAP has to be set to the correct address by executing a partial write cycle  
which finishes (CS high) immediately after the MAP byte. The MAP auto increment bit (INCR)  
may be set or not, as desired. To begin a read, bring CS low, send out the chip address and set  
CS  
C C L K  
C H IP  
C H IP  
M A P  
DATA  
A D D R E S S  
ADDRESS  
0010000  
0010000  
LSB  
MSB  
b y te 1  
R/W  
R/W  
C D IN  
b yte n  
High Impedance  
LSB  
MSB  
LSB  
MSB  
C D O U T  
MAP = Memory Address Pointer, 8 bits, MSB first  
Figure 9. Control Port Timing in SPI Mode  
DS580F1  
19  
CS8406  
the read/write bit (R/W) high. The next falling edge of CCLK will clock out the MSB of the ad-  
dressed register (CDOUT will leave the high impedance state). If the MAP auto increment bit is  
set to 1, the data for successive registers will appear consecutively.  
6.2. I²C Mode  
In I²C mode, SDA is a bidirectional data line. Data is clocked into and out of the part by the clock,  
SCL. There is no CS pin. Pins AD0, AD1, and AD2 form the three least significant bits of the chip  
address and should be connected through a resistor to VL or GND as desired.  
The signal timings for a read and write cycle are shown in Figure 10 and Figure 11. A Start con-  
dition is defined as a falling transition of SDA while the clock is high. A Stop condition is a rising  
transition while the clock is high. All other transitions of SDA occur while the clock is low. The first  
byte sent to the CS8406 after a Start condition consists of a 7 bit chip address field and a R/W  
bit (high for a read, low for a write). The upper 4 bits of the 7-bit address field are fixed at 0010.  
To communicate with a CS8406, the chip address field, which is the first byte sent to the CS8406,  
should match 0010 followed by the settings of the AD2, AD1, and AD0 pins. The eighth bit of the  
address is the R/W bit. If the operation is a write, the next byte is the Memory Address Pointer  
(MAP) which selects the register to be read or written. If the operation is a read, the contents of  
the register pointed to by the MAP will be output. Setting the auto increment bit in MAP allows  
successive reads or writes of consecutive registers. Each byte is separated by an acknowledge  
bit (ACK). The ACK bit is output from the CS8406 after each input byte is read, and is input to  
the CS8406 from the microcontroller after each transmitted byte.  
26  
27 28  
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19  
24 25  
SCL  
SDA  
DATA +1  
DATA +n  
CHIP ADDRESS (WRITE)  
AD2 AD1 AD0  
MAP BYTE  
DATA  
0
0
1
0
0
INCR  
6
5
4
3
2
1
0
7
6
1
0
7
6
1
0
7
6
1
0
ACK  
ACK  
ACK  
ACK  
STOP  
START  
Figure 10. Control Port Timing, I²C Slave Mode Write  
0
1
2
3
4
5
6
7
0
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25  
26 27 28  
SCL  
SDA  
STOP  
CHIP ADDRESS (WRITE)  
AD2 AD1 AD0  
MAP BYTE  
CHIP ADDRESS (READ)  
AD2 AD1 AD0 1  
DATA  
DATA +1 DATA + n  
0
0
1
0
INCR  
6
5
4
3
2
1
0
0
0
1
0
7
0
7
0
7
0
ACK  
ACK  
START  
ACK  
ACK  
NO  
ACK  
START  
STOP  
Figure 11. Control Port Timing, I²C Slave Mode Read  
Since the read operation can not set the MAP, an aborted write operation is used as a preamble.  
As shown in Figure 11, the write operation is aborted after the acknowledge for the MAP byte by  
sending a stop condition. The following pseudocode illustrates an aborted write operation fol-  
lowed by a read operation.  
20  
DS580F1  
CS8406  
Send start condition.  
Send 0010xxx0 (chip address & write operation).  
Receive acknowledge (ACK) bit.  
Send MAP byte, auto increment off.  
Receive ACK bit.  
Send stop condition, aborting write.  
Send start condition.  
Send 0010xxx(chip address & read operation).  
Receive ACK bit.  
Receive byte, contents of selected register.  
Send no acknowledge (NO ACK) bit.  
Send stop condition.  
Setting the auto increment bit in the MAP allows successive reads or writes of consecutive reg-  
isters. Each byte is separated by an acknowledge bit.  
6.3. Memory Address Pointer (MAP)  
6.3.1. Memory Address Pointer (MAP) Register Detail  
7
6
5
4
3
2
1
0
INCR  
MAP6  
MAP5  
MAP4  
MAP3  
MAP2  
MAP1  
MAP0  
6.3.2. INCR (Auto Map Increment Enable)  
Default = ‘0’  
0 - Disabled, the MAP will stay constant for successive writes  
1 - Enabled, the MAP will auto increment after each byte is written, allowing block reads  
or writes of successive registers  
6.3.3. MAP6-0 (Memory Address Pointer)  
Default = ‘0000000’  
DS580F1  
21  
CS8406  
7. CONTROL PORT REGISTER SUMMARY  
Addr  
Function  
7
6
5
4
3
2
1
0
(HEX)  
00 Reserved  
01 Control 1  
02 Control 2  
0
0
0
0
0
0
VSET  
0
TXOFF AESBP  
RUN CLK1  
SISF SIRES1  
0
0
0
0
0
0
0
0
0
0
INT1  
0
INT0  
0
MUTEAES  
TCBLD  
0
0
MMT MMCST MMTLR  
0
0
03 Data Flow Control  
04 Clock Source Control  
05 Serial Input Format  
06 Reserved  
07 Interrupt 1 Status  
08 Interrupt 2 Status  
09 Interrupt 1 Mask  
0A Interrupt 1 Mode (MSB) TSLIP1  
0B Interrupt 1 Mode (LSB) TSLIP0  
0C Interrupt 2 Mask  
0D Interrupt 2 Mode (MSB)  
0E Interrupt 2 Mode (LSB)  
0F-11 Reserved  
0
0
0
0
CLK0  
SIMS  
0
TSLIP  
0
SIRES0 SIJUST SIDEL SISPOL SILRPOL  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
UD  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
EFTU  
0
EFTC  
0
TSLIPM  
EFTCM  
EFTC1  
EFTC0  
0
0
0
0
CAM  
0
0
0
0
0
0
0
0
0
0
EFTUM  
EFTU1  
EFTU0  
0
0
0
0
0
BSEL  
0
12 CS Data Buffer Control  
13 U Data Buffer Control  
1D-1F Reserved  
EFTCI  
0
EFTUI  
0
UBM1 UBM0  
0
0
0
0
20-37 C or U Data Buffer  
7F ID and Version  
ID3  
ID2  
ID1  
ID0  
VER3  
VER2  
VER1  
VER0  
Table 1. Control Register Map Summary  
Notes:  
Reserved registers must not be written to during normal operation. Some reserved registers are used  
for test modes, which can completely alter the normal operation of the CS8406.  
22  
DS580F1  
CS8406  
8. CONTROL PORT REGISTER BIT DEFINITIONS  
8.1  
Control 1 (01h)  
7
0
6
5
0
4
3
0
2
INT1  
1
INT0  
0
VSET  
MUTEAES  
TCBLD  
VSET - Transmitted Validity bit level  
Default = ‘0’  
0 - Indicates data is valid, linear PCM audio data  
1 - Indicates data is invalid or not linear PCM audio data  
MUTEAES - Mute control for the AES transmitter output  
Default = ‘0’  
0 - Not Muted  
1 - Muted  
INT1:0 - Interrupt output pin (INT) control  
Default = ‘00’  
00 - Active high; high output indicates interrupt condition has occurred  
01 - Active low, low output indicates an interrupt condition has occurred  
10 - Open drain, active low. Requires an external pull-up resistor on the INT pin.  
11 - Reserved  
TCBLD - Transmit Channel Status Block pin (TCBL) direction specifier  
Default = ‘0’  
0 - TCBL is an input  
1 - TCBL is an output  
DS580F1  
23  
CS8406  
8.2  
Control 2 (02h)  
7
0
6
0
5
0
4
0
3
0
2
MMT  
1
0
MMTCS  
MMTLR  
MMT - Select AES3 transmitter mono or stereo operation  
Default = ‘0’  
0 - Normal stereo operation  
1 - Output either left or right channel inputs into consecutive subframe outputs (mono  
mode, left or right is determined by MMTLR bit)  
MMTCS - Select A or B channel status data to transmit in mono mode  
Default = ‘0’  
0 - Use channel A CS data for the A subframe and use channel B CS data for the B subframe  
1 - Use the same CS data for both the A and B subframe outputs. If MMTLR = 0, use the  
left channel CS data. If MMTLR = 1, use the right channel CS data.  
MMTLR - Channel Selection for AES Transmitter mono mode  
Default = ‘0’  
0 - Use left channel input data for consecutive subframe outputs  
1- Use right channel input data for consecutive subframe outputs  
8.3  
Data Flow Control (03h)  
7
0
6
5
4
0
3
0
2
0
1
0
0
0
TXOFF  
AESBP  
The Data Flow Control register configures the flow of audio data. The output data should be muted prior to changing  
bits in this register to avoid transients.  
TXOFF - AES3 Transmitter Output Driver Control  
Default = ‘0  
0 - AES3 transmitter output pin drivers normal operation  
1 - AES3 transmitter output pin drivers drive to 0 V.  
AESBP - AES3 bypass mode selection  
Default = ‘0’  
0 - Normal operation  
1 - Connect the AES3 transmitter driver input directly to the RXP pin, which becomes a normal TTL  
threshold digital input.  
24  
DS580F1  
CS8406  
8.4  
Clock Source Control (04h)  
7
0
6
RUN  
5
4
3
0
2
0
1
0
0
0
CLK1  
CLK0  
This register configures the clock sources of various blocks. In conjunction with the Data Flow Control register, var-  
ious Receiver/Transmitter/Transceiver modes may be selected.  
RUN - Controls the internal clocks, allowing the CS8406 to be placed in a “powered down” low  
current consumption, state.  
Default = ‘0’  
0 - Internal clocks are stopped. Internal state machines are reset. The fully static  
control port registers are operational, allowing registers to be read or changed. Reading and  
writing the U and C data buffers is not possible. Power consumption is low.  
1 - Normal part operation. This bit must be set to 1 to allow the CS8406 to begin operation.  
All input clocks should be stable in frequency and phase when RUN is set to 1.  
CLK1:0 - Output master clock (OMCK) input frequency to output sample rate (Fs) ratio selector.  
If these bits are changed during normal operation, then always stop the CS8406 first (RUN = 0),  
write the new value, then start the CS8406 (RUN = 1).  
Default = ‘00’  
00 - OMCK frequency is 256*Fs  
01 - OMCK frequency is 384*Fs  
10 - OMCK frequency is 512*Fs  
11 - OMCK frequency is 128*Fs  
8.5  
Serial Audio Input Port Data Format (05h)  
7
6
SISF  
5
4
3
2
1
0
SIMS  
SIRES1  
SIRES0  
SIJUST  
SIDEL  
SISPOL  
SILRPOL  
SIMS - Master/Slave Mode Selector  
Default = ‘0’  
0 - Serial audio input port is in slave mode  
1 - Serial audio input port is in master mode  
SISF - ISCLK frequency (for master mode)  
Default = ‘0’  
0 - 64*Fs  
1 - 128*Fs  
SIRES1:0 - Resolution of the input data, for right-justified formats  
Default = ‘00’  
00 - 24-bit resolution  
01 - 20-bit resolution  
10 - 16-bit resolution  
11 - Reserved  
DS580F1  
25  
CS8406  
SIJUST - Justification of SDIN data relative to ILRCK  
Default = ‘0’  
0 - Left-justified  
1 - Right-justified  
SIDEL - Delay of SDIN data relative to ILRCK, for left-justified data formats  
Default = ‘0’  
0 - MSB of SDIN data occurs in the first ISCLK period after the ILRCK edge (left justified mode)  
1 - MSB of SDIN data occurs in the second ISCLK period after the ILRCK edge (I²S mode)  
SISPOL - ISCLK clock polarity  
Default = ‘0’  
0 - SDIN sampled on rising edges of ISCLK  
1 - SDIN sampled on falling edges of ISCLK  
SILRPOL - ILRCK clock polarity  
Default = ‘0’  
0 - SDIN data is for the left channel when ILRCK is high  
1 - SDIN data is for the right channel when ILRCK is high  
8.6  
Interrupt 1 Status (07h) (Read Only)  
7
6
0
5
0
4
0
3
0
2
0
1
0
0
TSLIP  
EFTC  
For all bits in this register, a ‘1’ means the associated interrupt condition has occurred at least once since the register  
was last read. A ‘0’ means the associated interrupt condition has NOT occurred since the last reading of the register.  
Reading the register resets all bits to ‘0’, unless the interrupt mode is set to level and the interrupt source is still true.  
Status bits that are masked off in the associated mask register will always be ‘0’ in this register. This register defaults  
to 00h.  
TSLIP - AES3 transmitter source data slip interrupt  
In data flows where OMCK, which clocks the AES3 transmitter, is asynchronous to the data source,  
this bit will go high every time a data sample is dropped or repeated. When TCBL is an input, this bit  
will go high on receipt of a new TCBL signal.  
EFTC - E to F C-buffer transfer interrupt.  
The source for this bit is true during the E to F buffer transfer in the C bit buffer management process.  
26  
DS580F1  
CS8406  
8.7  
Interrupt 2 Status (08h) (Read Only)  
7
0
6
0
5
0
4
0
3
0
2
1
0
0
0
EFTU  
For all bits in this register, a ‘1’ means the associated interrupt condition has occurred at least once since the register  
was last read. A ‘0’ means the associated interrupt condition has NOT occurred since the last reading of the register.  
Reading the register resets all bits to ‘0’, unless the interrupt mode is set to level and the interrupt source is still true.  
Status bits that are masked off in the associated mask register will always be ‘0’ in this register. This register defaults  
to 00h.  
EFTU - E to F U-buffer transfer interrupt. (Block Mode only)  
The source of this bit is true during the E to F buffer transfer in the U bit buffer management process.  
8.8  
Interrupt 1 Mask (09h)  
7
6
0
5
0
4
0
3
0
2
0
1
0
0
TSLIPM  
EFTCM  
The bits of this register serve as a mask for the Interrupt 1 register. If a mask bit is set to 1, the error is unmasked,  
meaning that its occurrence will affect the INT pin and the status register. If a mask bit is set to 0, the error is masked,  
meaning that its occurrence will not affect the INT pin or the status register. The bit positions align with the corre-  
sponding bits in Interrupt 1 register. This register defaults to 00h.  
8.9  
Interrupt 1 Mode MSB (0Ah) and Interrupt 1 Mode LSB (0Bh)  
7
6
0
0
5
0
0
4
0
0
3
0
0
2
0
0
1
0
0
0
TSLIP1  
TSLIP0  
EFTC1  
EFTC0  
The two Interrupt Mode registers form a 2-bit code for each Interrupt Register 1 function. There are three ways to  
set the INT pin active in accordance with the interrupt condition. In the Rising edge active mode, the INT pin be-  
comes active on the arrival of the interrupt condition. In the Falling edge active mode, the INT pin becomes active  
on the removal of the interrupt condition. In Level active mode, the INT interrupt pin becomes active during the in-  
terrupt condition. Be aware that the active level (Active High or Low) only depends on the INT[1:0] bits. These reg-  
isters default to 00.  
00 - Rising edge active  
01 - Falling edge active  
10 - Level active  
11 - Reserved  
8.10 Interrupt 2 Mask (0Ch)  
7
0
6
0
5
0
4
0
3
0
2
1
0
0
0
EFTUM  
The bits of this register serve as a mask for the Interrupt 2 register. If a mask bit is set to 1, the error is unmasked,  
meaning that its occurrence will affect the INT pin and the status register. If a mask bit is set to 0, the error is masked,  
meaning that its occurrence will not affect the INT pin or the status register. The bit positions align with the corre-  
sponding bits in Interrupt 2 register. This register defaults to 00h.  
DS580F1  
27  
CS8406  
8.11 Interrupt 2 Mode MSB (0Dh) and Interrupt Mode 2 LSB (0Eh)  
7
0
0
6
0
0
5
0
0
4
0
0
3
0
0
2
1
0
0
0
0
0
EFTU1  
EFTU0  
The two Interrupt Mode registers form a 2-bit code for each Interrupt Register 1 function. There are three ways to  
set the INT pin active in accordance with the interrupt condition. In the Rising edge active mode, the INT pin be-  
comes active on the arrival of the interrupt condition. In the Falling edge active mode, the INT pin becomes active  
on the removal of the interrupt condition. In Level active mode, the INT interrupt pin becomes active during the in-  
terrupt condition. Be aware that the active level (Active High or Low) only depends on the INT[1:0] bits. These reg-  
isters default to 00.  
00 - Rising edge active  
01 - Falling edge active  
10 - Level active  
11 - Reserved  
8.12 Channel Status Data Buffer Control (12h)  
7
0
6
0
5
4
0
3
0
2
1
CAM  
0
0
BSEL  
EFTCI  
BSEL - Selects the data buffer register addresses to contain User data or Channel Status data  
Default = ‘0’  
0 - Data buffer address space contains Channel Status data  
1 - Data buffer address space contains User data  
Note: There are separate complete buffers for the Channel Status and User bits. This control bit determines which  
buffer appears in the address space.  
EFTCI - E to F C-data buffer transfer inhibit bit.  
Default = ‘0’  
0 - Allow C-data E to F buffer transfers  
1 - Inhibit C-data E to F buffer transfers  
CAM - C-data buffer control port access mode bit  
Default = ‘0’  
0 - One byte mode  
1 - Two byte mode  
28  
DS580F1  
CS8406  
8.13 User Data Buffer Control (13h)  
7
0
6
0
5
0
4
UD  
3
2
1
0
0
UBM1  
UBM0  
EFTUI  
UD - User bit data source specifier  
Default = ‘0’  
0 - U Pin is the source of transmitted U data  
1 - U data buffer is the source of transmitted U data  
UBM1:0 - Sets the operating mode of the AES3 User bit manager  
Default = ‘00’  
00 - Transmit all zeros mode  
01 - Block mode  
10 - Reserved  
11 - Reserved  
EFTUI - E to F U-data buffer transfer inhibit bit (valid in block mode only).  
Default = ‘0’  
0 - Allow U-data E to F buffer transfers  
1 - Inhibit U-data E to F buffer transfers  
8.14 Channel Status bit or User bit Data Buffer (20h - 37h)  
Either the channel status data buffer E or the separate user bit data buffer E (provided UBM bits are set to block  
mode) is accessible through these register addresses.  
8.15 CS8406 I.D. and Version Register (7Fh) (Read Only)  
7
ID3  
6
ID2  
5
ID1  
4
ID0  
3
2
1
0
VER3  
VER2  
VER1  
VER0  
ID[3:0] - ID code for the CS8406. Permanently set to 1110  
VER[3:0] = 0001 (revision A)  
VER[3:0] = 0010 (revision B)  
DS580F1  
29  
CS8406  
9. PIN DESCRIPTION - SOFTWARE MODE  
SDA / CDOUT  
AD0 / CS  
AD2  
SCL / CCLK  
1
28  
27  
26  
25  
24  
23  
22  
21  
20  
19  
18  
17  
16  
15  
AD1 / CDIN  
TXP  
2
3
RXP  
TXN  
4
TEST  
H/S  
5
VD  
VL  
6
TEST  
GND  
OMCK  
U
7
TEST  
8
RST  
9
TEST  
INT  
10  
11  
12  
13  
14  
TEST  
TEST  
TEST  
TEST  
TCBL  
ILRCK  
ISCLK  
SDIN  
VD  
6
Digital Power (Input) - Digital core power supply. Typically +3.3 V or +5.0 V.  
VL  
23 Logic Power (Input) - Input/Output power supply. Typically +3.3 V or +5.0 V.  
GND  
22  
9
Ground (Input) - Ground for I/O and core logic.  
Reset (Input) - When RST is low, the CS8406 enters a low power mode and all internal states are reset.  
On initial power up, RST must be held low until the power supply is stable, and all input clocks are stable  
in frequency and phase. This is particularly true in hardware mode with multiple CS8406 devices, where  
synchronization between devices is important.  
RST  
H/S  
24 Hardware/Software Control Mode Select (Input) -Determines the method of controlling the operation  
of the CS8406, and the method of accessing CS and U data. In software mode, device control and CS  
and U data access is primarily through the control port, using a microcontroller. To select Software  
mode, this pin should be permanently tied to GND.  
TXN  
TXP  
25 Differential Line Drivers (Output) - These pins transmit biphase encoded data. The drivers are pulled  
26 low while the CS8406 is in the reset state.  
OMCK  
ISCLK  
ILRCK  
21 Master Clock (Input) - The frequency can be set through the control port registers.  
13 Serial Audio Bit Clock (Input/Output) - Serial bit clock for audio data on the SDIN pin.  
12 Serial Audio Input Left/Right Clock (Input/Output) - Word rate clock for the audio data on the SDIN  
pin.  
SDIN  
14 Serial Audio Data Port (Input) - Audio data serial input pin.  
30  
DS580F1  
CS8406  
SDA/CDOUT  
1
Serial Control Data I/O (I²C Mode) / Data Out (SPI) (Input/Output) - In I²C Mode, SDA is the control I/O  
data line. SDA is open drain and requires an external pull-up resistor to VL. In SPI mode, CDOUT is the  
output data from the control port interface on the CS8406  
SCL/CCLK  
AD0/CS  
28 Control Port Clock (Input) - Serial control interface clock and is used to clock control data bits into and  
out of the CS8406. In I²C mode, SCL requires an external pull-up resistor to VL.  
2
Address Bit 0 (I²C Mode) / Control Port Chip Select (SPI) (Input) - A falling edge on this pin puts the  
CS8406 into SPI control port mode. With no falling edge, the CS8406 defaults to I²C mode. In I²C mode,  
AD0 is a chip address pin. In SPI mode, CS is used to enable the control port interface on the CS8406  
AD1/CDIN  
AD2  
27 Address Bit 1 (I²C Mode) / Serial Control Data in (SPI) (Input) - In I²C mode, AD1 is a chip address  
pin. In SPI mode, CDIN is the input data line for the control port interface.  
3
Address Bit 2 (I²C Mode) (Input) - Determines the AD2 address bit for the control port in I²C mode, and  
should be connected to GND or VL. If SPI mode is used, the AD2 pin should be connected to either  
GND or VL.  
RXP  
INT  
4
Auxiliary AES3 Receiver Port (Input) - Input for an alternate, already AES3 coded, audio data source.  
19 Interrupt (Output) - Indicates key events during the operation of the CS8406. All bits affecting INT may  
be unmasked through bits in the control registers. Indication of the condition(s) that initiated an interrupt  
are readable in the control registers. The polarity of the INT output, as well as selection of a standard or  
open drain output, is set through a control register. Once set true, the INT pin goes false only after the  
interrupt status registers have been read and the interrupt status bits have returned to zero.  
TCBL  
15 Transmit Channel Status Block Start (Input/Output) - When operated as output, TCBL is high during  
the first sub-frame of a transmitted channel status block, and low at all other times. When operated as  
input, driving TCBL high for at least three OMCK clocks will cause the next transmitted sub-frame to be  
the start of a channel status block.  
U
20 User Data (Input) - May optionally be used to input User data for transmission by the AES3 transmitter,  
see Figure 4 for timing information. If not driven, a 47 kpull-down resistor is recommended for the U  
pin. If the U pin is driven by a logic level output, then a 100 series resistor is recommended.  
TEST  
7
8
Test Pins - These pins are unused inputs. It is recommended that these pins be tied to a supply (VL or  
GND) to minimize leakage current. The CS8406 will operate correctly if these pins are left floating, how-  
10 ever current consumption from VL will increase by 25 µA per TEST pin that is left floating.  
11  
16  
17  
18  
DS580F1  
31  
CS8406  
10.HARDWARE MODE  
The CS8406 has a hardware mode that allows the use of the device without a microcontroller.  
Hardware mode is selected by connecting the H/S pin to VL. The flexibility of the CS8406 is nec-  
essarily limited in hardware mode. Various pins change function as described in the hardware  
mode pin description section.  
The hardware mode data flow is shown in Figure 12. Audio data is input through the serial audio  
input port and routed to the AES3 transmitter.  
10.1 Channel Status, User and Validity Data  
The transmitted channel status, user and validity data can be input in two methods, determined  
by the state of the CEN pin. Mode A is selected when the CEN pin is low. In mode A, the user bit  
data and the validity bit are input through the U and V pins, clocked by both edges of ILRCK. The  
channel status data is derived from the state of the COPY/C, ORIG, EMPH, and AUDIO pins.  
Table 2 shows how the COPY/C and ORIG pins map to channel status bits. In consumer mode,  
the transmitted category code is set to General (00h).  
Mode B is selected when the CEN pin is high. In mode B, the channel status, user data bits and  
the validity bit are input serially through the COPY/C, U and V pins. Data is clocked into these  
pins at both edges of ILRCK. Figure 8 shows the timing requirements.  
VL  
Output  
Clock  
Source  
RST  
H/S  
OMCK  
TCBLD  
ILRCK  
ISCLK  
SDIN  
TXP  
TXN  
TCBL  
Serial  
Audio  
Input  
AES3  
Encoder  
& Tx  
CEN  
U
C, U, V Data Buffer  
V
APMS SFMT1 SFMT0  
COPY/C  
ORIG EMPH AUDIO  
Power supply pins are omitted from this diagram.  
Please refer to the Typical Connection Diagram for hook-up details.  
Figure 12. Hardware Mode Data Flow  
32  
DS580F1  
CS8406  
The channel status block pin (TCBL) may be an input or an output, determined by the state of  
the TCBLD pin.  
COPY/C  
ORIG  
Function  
0
0
1
1
0
1
0
1
PRO=0, COPY=0, L=0 copyright  
PRO=0, COPY=0, L=1 copyright, pre-recorded  
PRO=0, COPY=1, L=0 non-copyright  
PRO=1  
Table 2. Hardware Mode COPY/C and ORIG pin functions  
10.2 Serial Audio Port  
The serial audio input port data format is selected as shown in Table 3, and may be set to master  
or slave by the state of the APMS input pin. The OMCK clock ratio is selected as shown in  
Table 4. Table 5 describes the equivalent software mode, bit settings for each of the available for-  
mats. Timing diagrams are shown in Figure 7.  
SFMT1 SFMT0  
Function  
0
0
1
1
0
1
0
1
Serial Input Format IF1 - Left Justified  
Serial Input Format IF2 - I²S  
Serial Input Format IF3 - Right Justified, 24-bit data  
Serial Input Format IF4 - Right Justified, 16-bit data  
Table 3. Hardware Mode Serial Audio Port Format Selection  
HWCK1 HWCK0  
Function  
0
0
1
1
0
1
0
1
OMCK Frequency is 256*Fs  
OMCK Frequency is 128*Fs  
OMCK Frequency is 512*Fs  
OMCK Frequency is 256*Fs  
Table 4. Hardware Mode OMCK Clock Ratio Selection  
SISF SIRES1/0 SIJUST SIDEL SISPOL SILRPOL  
IF1 - Left Justified  
IF2 - I²S  
IF3 - Right Justified, 24-bit data  
IF4 - Right Justified, 16-bit data  
0
0
0
0
00  
00  
00  
10  
0
0
1
1
0
1
0
0
0
0
0
0
0
1
0
0
Table 5. Equivalent Register Settings of Serial Audio Input Formats Available in Hardware Mode  
DS580F1  
33  
CS8406  
11.PIN DESCRIPTION - HARDWARE MODE  
COPY / C  
TEST  
ORIG  
HWCK1  
TXP  
1
28  
27  
26  
25  
24  
23  
22  
21  
20  
19  
18  
17  
16  
15  
2
EMPH  
SFMT0  
SFMT1  
VD  
3
TXN  
4
H/S  
5
VL  
6
TEST  
GND  
OMCK  
HWCK0  
AUDIO  
U
7
TEST  
8
RST  
9
APMS  
TCBLD  
ILRCK  
ISCLK  
SDIN  
10  
11  
12  
13  
14  
V
CEN  
TCBL  
VD  
6
Digital Power (Input) - Digital core power supply. Typically +3.3 V or +5.0 V.  
VL  
23 Logic Power (Input) - Input/Output power supply. Typically +3.3 V or +5.0 V.  
GND  
22  
9
Ground (Input) - Ground for I/O and core logic.  
Reset (Input) - When RST is low, the CS8406 enters a low power mode and all internal states are reset.  
On initial power up, RST must be held low until the power supply is stable, and all input clocks are stable  
in frequency and phase. This is particularly true in hardware mode with multiple CS8406 devices, where  
synchronization between devices is important.  
RST  
H/S  
24 Hardware/Software Control Mode Select (Input) -Determines the method of controlling the operation  
of the CS8406, and the method of accessing CS and U data. Hardware mode provides an alternate  
mode of operation, and access to CS and U data is provided by dedicated pins. To select Hardware  
mode, this pin should be permanently tied to VL.  
TXN  
TXP  
25 Differential Line Drivers (Output) - These pins transmit biphase encoded data. The drivers are pulled  
26 low while the CS8406 is in the reset state.  
OMCK  
ISCLK  
ILRCK  
21 Master Clock (Input) - The frequency can be set through the HWCK[1:0] pins.  
13 Serial Audio Bit Clock (Input/Output) - Serial bit clock for audio data on the SDIN pin.  
12 Serial Audio Input Left/Right Clock (Input/Output) - Word rate clock for the audio data on the SDIN  
pin.  
SDIN  
14 Serial Audio Data Port (Input) - Audio data serial input pin.  
SFMT0  
SFMT1  
4
5
Serial Audio Data Format Select (Input) - Selects the serial audio input port format. See Table 3 on  
page 33.  
34  
DS580F1  
CS8406  
APMS  
10 Serial Audio Data Port Master/Slave Select (Input) - APMS should be connected to VL to set serial  
audio input port as a master or connected to GND to set the port as a slave.  
HWCK0  
HWCK1  
20 OMCK Clock Ratio Select (Input) - Selects the ratio of OMCK to the input sample rate (Fs). A pull-up to  
27 VL or pull-down to GND is required to set the appropriate mode. See Table 4 on page 33.  
TCBLD  
11 Transmit Channel Status Block Direction (Input) - Connect TCBLD to VL to set TCBL as an output.  
Connect TCBLD to GND to set TCBL as an input.  
TCBL  
15 Transmit Channel Status Block Start (Input/Output) - When operated as output, TCBL is high during  
the first sub-frame of a transmitted channel status block, and low at all other times. When operated as  
input, driving TCBL high for at least three OMCK clocks will cause the next transmitted sub-frame to be  
the start of a channel status block.  
CEN  
16 C Bit Enable (Input) - Determines how the channel status data bits are input. When CEN is low, hard-  
ware mode A is selected, where the COPY/C, ORIG, EMPH and AUDIO pins are used to enter selected  
channel status data. When CEN is high, hardware mode B is selected, where the COPY/C pin is used to  
enter serial channel status data.  
V
17 Validity Bit (Input) - In hardware modes A and B, the V pin input determines the state of the validity bit  
in the outgoing AES3 transmitted data. This pin is sampled on both edges of the ILRCK.  
U
18 User Data Bit (Input) - In hardware modes A and B, the U pin input determines the state of the user  
data bit in the outgoing AES3 transmitted data. This pin is sampled on both edges of the ILRCK.  
COPY/C  
1
COPY Channel Status Bit/C Bit (Input) - In hardware mode A (CEN = 0), the COPY/C and ORIG pins  
determine the state of the Copyright, Pro, and L Channel Status bits in the outgoing AES3 data stream,  
see Table 2 on page 33. In hardware mode B, the COPY/C pin becomes the direct C bit input data pin,  
which is sampled on both edges of LRCK.  
3
Pre-Emphasis Indicator (Input) - In hardware mode A (CEN = 0), the EMPH pin low sets the 3 empha-  
sis channel status bits to indicate 50/15 µs pre-emphasis of the transmitted audio data. If EMPH is high,  
then the three EMPH channel status bits are set to 000, indicating no pre-emphasis.  
EMPH  
19 Audio Channel Status Bit (Input) - In hardware mode A (CEN = 0), the AUDIO pin determines the state  
AUDIO  
ORIG  
of the audio/non audio Channel Status bit in the outgoing AES3 data stream.  
28 ORIG Channel Status Bit Control (Input) - In hardware mode A (CEN = 0), the ORIG and COPY/C  
pins determine the state of the Copyright, Pro, and L Channel Status bits in the outgoing AES3 data  
stream, see Table 2 on page 33.  
TEST  
2
7
8
Test Pins - These pins are unused inputs. It is recommended that these pins be tied to a supply (VL or  
GND) to minimize leakage current. The CS8406 will operate correctly if these pins are left floating, how-  
ever current consumption from VL will increase by 25 µA per TEST pin that is left floating.  
DS580F1  
35  
CS8406  
12.APPLICATIONS  
12.1 Reset, Power Down and Start-up  
When RST is low, the CS8406 enters a low power mode and all internal states are reset, includ-  
ing the control port and registers, and the outputs are disabled. In Software mode when RST is  
high, the control port becomes operational and the desired settings should be loaded into the  
control registers. Writing a 1 to the RUN bit will then cause the part to leave the low power state  
and begin operation. In Hardware mode when RST is high, the part will automatically leave the  
low power state and begin operation.  
12.2 ID Code and Revision Code  
The CS8406 has a register that contains a four-bit code to indicate that the addressed device is  
a CS8406. This is useful when other CS84XX family members are resident in the same or similar  
systems, allowing common software modules.  
The CS8406 four-bit revision level code is also available. This allows the software driver for the  
CS8406 to identify which revision of the device is in a particular system, and modify its behavior  
accordingly. To allow for future revisions, it is strongly recommended that the revision code is  
read into a variable area within the microcontroller, and used wherever appropriate as revision  
details become known.  
12.3 Power Supply, Grounding, and PCB layout  
The CS8406 operates from a VD = +3.3 V or +5.0 V and VL = +3.3 V or +5.0 V supply. These  
supplied may be set independently. Follow normal supply decoupling practices, see Figure 5 and  
Figure 6. The VD and VL supplies should be decoupled with a 0.1 µF capacitor to GND to mini-  
mize AES3 transmitter induced transients.  
Extensive use of power and ground planes, ground plane fill in unused areas and surface mount  
decoupling capacitors are recommended. Decoupling capacitors should be mounted on the  
same side of the board as the CS8406 to minimize inductance effects, and all decoupling capac-  
itors should be as close to the CS8406 as possible.  
12.4 Synchronization of Multiple CS8406s  
The AES3 transmitters of multiple CS8406s can be synchronized if all devices share the same  
master clock, TCBL, and RST signals. The TCBL pin is used to synchronize multiple CS8406  
AES3 transmitters at the channel status block boundaries. One CS8406 must have its TCBL set  
to master; the others must be set to slave TCBL. Alternatively, TCBL can be derived from exter-  
nal logic, whereby all CS8406 devices should be set to slave TCBL.  
36  
DS580F1  
CS8406  
13. PACKAGE DIMENSIONS  
28L SOIC (300 MIL BODY) PACKAGE DRAWING  
E
H
1
b
c
D
L
SEATING  
PLANE  
A
e
A1  
INCHES  
NOM  
0.098  
0.008  
0.017  
0.011  
0.705  
0.295  
0.050  
0.407  
0.026  
4°  
MILLIMETERS  
NOM  
2.50  
DIM  
A
A1  
b
C
D
E
e
H
L
MIN  
0.093  
0.004  
0.013  
0.009  
0.697  
0.291  
0.040  
0.394  
0.016  
0°  
MAX  
0.104  
0.012  
0.020  
0.013  
0.713  
0.299  
0.060  
0.419  
0.050  
8°  
MIN  
2.35  
0.10  
0.33  
0.23  
17.70  
7.40  
1.02  
10.00  
0.40  
0°  
MAX  
2.65  
0.30  
0.51  
0.32  
18.10  
7.60  
1.52  
10.65  
1.27  
8°  
0.20  
0.42  
0.28  
17.90  
7.50  
1.27  
10.34  
0.65  
4°  
JEDEC #: MS-013  
Controlling Dimension is Millimeters  
DS580F1  
37  
CS8406  
28L TSSOP (4.4 mm BODY) PACKAGE DRAWING  
N
D
E11  
A2  
A
E
A1  
b2  
e
L
END VIEW  
SEATING  
PLANE  
SIDE VIEW  
1
2
3
TOP VIEW  
INCHES  
MILLIMETERS  
NOTE  
DIM  
A
A1  
A2  
b
D
E
E1  
e
L
MIN  
NOM  
--  
0.004  
MAX  
0.47  
0.006  
0.04  
MIN  
--  
0.05  
0.80  
0.19  
NOM  
--  
0.10  
MAX  
1.20  
0.15  
1.00  
0.30  
--  
0.002  
0.03150  
0.00748  
0.378 BSC  
0.248  
0.169  
--  
0.035  
0.90  
0.0096  
0.382 BSC  
0.2519  
0.1732  
0.026 BSC  
0.024  
0.012  
0.386 BSC  
0.256  
0.177  
--  
0.245  
9.70 BSC  
6.40  
4.40  
0.65 BSC  
0.60  
2,3  
1
9.60 BSC  
6.30  
4.30  
--  
9.80 BSC  
6.50  
4.50  
--  
1
0.020  
0°  
0.029  
8°  
0.50  
0°  
0.75  
8°  
4°  
4°  
JEDEC #: MO-153  
Controlling Dimension is Millimeters.  
Notes: 1.“D” and “E1” are reference datums and do not included mold flash or protrusions, but do include mold  
mismatch and are measured at the parting line, mold flash or protrusions shall not exceed 0.20 mm per  
side.  
2.Dimension “b” does not include dambar protrusion/intrusion. Allowable dambar protrusion shall be  
0.13 mm total in excess of “b” dimension at maximum material condition. Dambar intrusion shall not  
reduce dimension “b” by more than 0.07 mm at least material condition.  
3.These dimensions apply to the flat section of the lead between 0.10 and 0.25 mm from lead tips.  
38  
DS580F1  
CS8406  
14.APPENDIX A: EXTERNAL AES3/SPDIF/IEC60958 TRANSMITTER  
COMPONENTS  
This section details the external components required to interface the AES3 transmitter to cables  
and fiber-optic components.  
14.1 AES3 Transmitter External Components  
The output drivers on the CS8406 are designed to drive both the professional and consumer in-  
terfaces. The AES3 and IEC60958-4 specifications call for a balanced output drive of 2-7 V peak-  
to-peak into a 110 20% load with no cable attached. Using the circuit in Figure 13, the output  
of the transformer is short-circuit protected, has the proper source impedance, and provides a  
5 V peak-to-peak signal into a 110 load. Lastly, the two output pins should be attached to an  
XLR connector with male pins and a female shell, and with pin 1 of the connector grounded.  
In the case of consumer use, the IEC60958-3 specification calls for an unbalanced drive circuit  
with an output impedance of 75 20% and a output drive level of 0.5 V peak-to-peak 20%  
when measured across a 75 load using no cable. The circuit shown in Figure 14 only uses the  
TXP pin and provides the proper output impedance and drive level using standard 1% resistors.  
If VL is set to +3.3 V, change 374 to 243 and change 90.9 to 107 . The connector for a  
consumer application would be an RCA phono socket. This circuit is also short circuit protected.  
The TXP pin may be used to drive TTL or CMOS gates as shown in Figure 15. This circuit may  
be used for optical connectors for digital audio since they usually have TTL or CMOS compatible  
inputs. This circuit is also useful when driving multiple digital audio outputs since RS422 line driv-  
ers have TTL compatible inputs.  
14.2 Isolating Transformer Requirements  
Please refer to the application note AN134: AES and SPDIF Recommended Transformers for re-  
sources on transformer selection.  
CS8406  
TXP  
CS8406  
TXP  
374-RTXP  
110-(RTXP+RTXN  
)
RCA  
Phono  
XLR  
90.9 Ω  
TXN  
TXN  
1
Figure 13. Professional Output Circuit  
Figure 14. Consumer Output Circuit (VL = 5.0 V)  
CS8406  
TXP  
TTL or  
CMOS Gate  
TXN  
Figure 15. TTL/CMOS Output Circuit  
DS580F1  
39  
CS8406  
15.APPENDIX B: CHANNEL STATUS AND USER DATA BUFFER MANAGEMENT  
The CS8406 has a comprehensive channel status (C) and user (U) data buffering scheme which  
allows the user to manage the C and U data through the control port.  
15.1 AES3 Channel Status(C) Bit Management  
The CS8406 contains sufficient RAM to store a full block of C data for both A and B channels  
(192x2 = 384 bits), and also 384 bits of U information. The user may read from or write to these  
RAM buffers through the control port.  
The CS8406 manages the flow of channel status data at the block level, meaning that entire  
blocks of channel status information are buffered at the input, synchronized to the output time-  
base, and then transmitted. The buffering scheme involves a cascade of 2 block-sized buffers,  
named E and F, as shown in Figure 16. The MSB of each byte represents the first bit in the serial  
C data stream. For example, the MSB of byte 0 (which is at control port address 20h) is the con-  
sumer/professional bit for channel status block A.  
The E buffer is accessible from the control port, allowing read and writing of the C data. The F  
buffer is used as the source of C data for the AES3 transmitter. The F buffer accepts block trans-  
fers from the E buffer.  
A
B
8-bits  
8-bits  
To  
AES3  
E
F
Transmitter  
24  
words  
Transmit  
Data  
Buffer  
Control Port  
Figure 16. Channel Status Data Buffer Structure  
15.1.1 Accessing the E buffer  
The user can monitor the data being transferred by reading the E buffer, which is mapped into  
the register space of the CS8406, through the control port. The user can modify the data to be  
transmitted by writing to the E buffer.  
The user can configure the interrupt enable register to cause interrupts to occur whenever “E to  
F” buffer transfers occur. This allows determination of the allowable time periods to interact with  
the E buffer.  
Also provided is an “E to F” inhibit bit. The “E to F” buffer transfer is disabled whenever the user  
sets this bit. This may be used whenever “long” control port interactions are occurring.  
A flowchart for reading and writing to the E buffer is shown in Figure 17. For writing, the sequence  
starts after a E to F transfer, which is based on the output timebase.  
40  
DS580F1  
CS8406  
If the channel status block to transmit indicates PRO mode, then the CRCC byte is automatically  
calculated by the CS8406, and does not have to be written into the last byte of the block by the  
host microcontroller. This is also true if the channel status data is entered serially through the  
COPY/C pin when the part is in hardware mode.  
E to F interrupt occurs  
Optionally set E to F inhibit  
Write E data  
If set, clear E to F inhibit  
Wait for E to F transfer  
Return  
Figure 17. Flowchart for Writing the E Buffer  
15.1.2 Serial Copy Management System (SCMS)  
In software mode, the CS8406 allows read/modify/write access to all the channel status bits. For  
consumer mode SCMS compliance, the host microcontroller needs to manipulate the Category  
Code, Copy bit and L bit appropriately.  
In hardware mode, the SCMS protocol can be followed by either using the COPY and ORIG input  
pins, or by using the C bit serial input pin. These options are documented in the hardware mode  
section of this data sheet.  
15.1.3 Channel Status Data E Buffer Access  
The E buffer is organized as 24 x 16-bit words. For each word the MS Byte is the A channel data,  
and the LS Byte is the B channel data (see Figure 16).  
There are two methods of accessing this memory, known as one byte mode and two byte mode.  
The desired mode is selected through a control register bit.  
15.1.3.1 One Byte mode  
In many applications, the channel status blocks for the A and B channels will be identical. In this  
situation, if the user reads a byte from one of the channel's blocks, the corresponding byte for the  
other channel will be the same. Similarly, if the user wrote a byte to one channel's block, it would  
be necessary to write the same byte to the other block. One byte mode takes advantage of the  
often identical nature of A and B channel status data.  
When reading data in one byte mode, a single byte is returned, which can be from channel A or  
B data, depending on a register control bit. If a write is being done, the CS8406 expects a single  
DS580F1  
41  
CS8406  
byte to be input to its control port. This byte will be written to both the A and B locations in the  
addressed word.  
One byte mode saves the user substantial control port access time, as it effectively accesses 2  
bytes worth of information in 1 byte's worth of access time. If the control port's auto increment  
addressing is used in combination with this mode, multi-byte accesses such as full-block reads  
or writes can be done especially efficiently.  
15.1.3.2 Two Byte mode  
There are those applications in which the A and B channel status blocks will not be the same,  
and the user is interested in accessing both blocks. In these situations, two byte mode should be  
used to access the E buffer.  
In this mode, a read will cause the CS8406 to output two bytes from its control port. The first byte  
out will represent the A channel status data, and the 2nd byte will represent the B channel status  
data. Writing is similar, in that two bytes must now be input to the CS8406's control port. The A  
channel status data is first, B channel status data second.  
15.2 AES3 User (U) Bit Management  
The CS8406 U bit manager has two operating modes:  
Mode 1. Transmit all zeros.  
Mode 2. Block mode.  
15.2.1 Mode 1: Transmit All Zeros  
Mode 1 causes only zeros to be transmitted in the output U data, regardless of E buffer contents.  
This mode is intended for the user who wants the output U channel to contain no data.  
15.2.2 Mode 2: Block Mode  
Mode 2 is very similar to the scheme used to control the C bits. Entire blocks of U data are buffered  
using 2 block-sized RAMs to perform the buffering. The user has access to the first buffer, denoted  
the E buffer, through the control port. It is the only mode in which the user can merge his own U data  
into the transmitted AES3 data stream. The U buffer access only operates in two byte mode, since  
there is no concept of A and B blocks for user data. The arrangement of the data is as followings:  
Bit15[A7] Bit14[B7] Bit13[A6] Bit12 [B6]...Bit1 [A0] Bit0[B0]. The arrangement of the data in the each  
byte is that the MSB is the first transmitted bit. The bit for the A subframe is followed by the bit for the  
B subframe.  
42  
DS580F1  
CS8406  
16. REVISION HISTORY  
Release  
PP1  
Date  
Changes  
August 2002  
May 2003  
1st Preliminary Release  
2nd Preliminary Release  
PP2  
PP3  
January 2004 -Corrected “OMCK Low and High Width for OMCK = 384*Fs” on page 7.  
-Corrected “Rise Time of Both SDA and SCL Lines” on page 10.  
-Corrected “Fall Time of Both SDA and SCL Lines” on page 10.  
-Added Note 13 on page 10.  
-Corrected Figure 6. “Recommended Connection Diagram for Hardware Mode” on  
page 12  
-Revised “Control Port Description” on page 19  
F1  
July 2004  
Final Release  
-Corrected “SDIN Setup Time Before ISCLK Active Edge” on page 7.  
-Corrected Note 5 on page 7.  
-Corrected Note 6 on page 7.  
-Added Figure 8. “AES3 Transmitter Timing for C, U, and V Pin Input Data” on page 18  
-Corrected H/S pin description on page 34.  
Table 6. Revision History  
Contacting Cirrus Logic Support  
For all product questions and inquiries contact a Cirrus Logic Sales Representative.  
To find the one nearest to you go to www.cirrus.com  
IIMPORTANT NOTICE  
Cirrus Logic, Inc. and its subsidiaries (“Cirrus”) believe that the information contained in this document is accurate and reliable. However, the information is subject  
to change without notice and is provided “AS IS” without warranty of any kind (express or implied). Customers are advised to obtain the latest version of relevant  
information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale  
supplied at the time of order acknowledgment, including those pertaining to warranty, patent infringement, and limitation of liability. No responsibility is assumed by  
Cirrus for the use of this information, including use of this information as the basis for manufacture or sale of any items, or for infringement of patents or other rights  
of third parties. This document is the property of Cirrus and by furnishing this information, Cirrus grants no license, express or implied under any patents, mask work  
rights, copyrights, trademarks, trade secrets or other intellectual property rights. Cirrus owns the copyrights associated with the information contained herein and  
gives consent for copies to be made of the information only for use within your organization with respect to Cirrus integrated circuits or other products of Cirrus. This  
consent does not extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale.  
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROP-  
ERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE  
IN AIRCRAFT SYSTEMS, MILITARY APPLICATIONS, PRODUCTS SURGICALLY IMPLANTED INTO THE BODY, LIFE SUPPORT PRODUCTS OR OTHER  
CRITICAL APPLICATIONS (INCLUDING MEDICAL DEVICES, AIRCRAFT SYSTEMS OR COMPONENTS AND PERSONAL OR AUTOMOTIVE SAFETY OR SE-  
CURITY DEVICES). INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK AND CIR-  
RUS DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND  
FITNESS FOR PARTICULAR PURPOSE, WITH REGARD TO ANY CIRRUS PRODUCT THAT IS USED IN SUCH A MANNER. IF THE CUSTOMER OR CUS-  
TOMER’S CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES, BY SUCH USE, TO FUL-  
LY INDEMNIFY CIRRUS, ITS OFFICERS, DIRECTORS, EMPLOYEES, DISTRIBUTORS AND OTHER AGENTS FROM ANY AND ALL LIABILITY, INCLUDING  
ATTORNEYS’ FEES AND COSTS, THAT MAY RESULT FROM OR ARISE IN CONNECTION WITH THESE USES.  
Cirrus Logic, Cirrus, and the Cirrus Logic logo designs are trademarks of Cirrus Logic, Inc. All other brand and product names in this document may be trademarks  
or service marks of their respective owners.  
I²C is a registered trademark of Philips Semiconductor. Purchase of I²C Components of Cirrus Logic, Inc., or one of its sublicensed Associated Companies conveys  
a license under the Philips I²C Patent Rights to use those components in a standard I²C system.  
DS580F1  
43  

相关型号:

CS8406/8416

TELECOMMUNICATIONS PRODUCTS
PULSE

CS8406_09

192 kHz Digital Audio Interface Transmitter
CIRRUS

CS8406_12

192 kHz Digital Audio Interface Transmitter
CIRRUS

CS841

MOV Modules
HVPSI

CS8411

DIGITAL AUDIO INTER FACE RECEIVER
CIRRUS

CS8411-CP

Digital Audio
ETC

CS8411-CS

Digital Audio Interface Receiver(555.21 k)
ETC

CS8411-IP

Digital Audio
ETC

CS8411-IS

Digital Audio Interface Receiver(555.21 k)
ETC

CS8412

DIGITAL AUDIO INTER FACE RECEIVER
CIRRUS

CS8412-CS

Digital Audio Interface Receiver(555.21 k)
ETC

CS8412-IP

Digital Audio Interface Receiver(555.21 k)
ETC