STAC9766 Datasheet, PDF (27/97 Pages) Integrated Device Technology – TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH STEREO MICROPHONE AND MIC/JACK SENSING

STAC9766/9767
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH STEREO MICROPHONE AND MIC/JACK SENSING
PC AUDIO
5. AC-LINK DIGITAL INTERFACE
5.1. Overview
AC-link is the 5 pin digital serial interface that links AC‘97 CODEC to Controller. The AC-link protocol
is a bi-directional, fixed clock rate, serial digital stream. AC-link handles multiple input and output
PCM audio streams, as well as control register accesses, employing a time division multiplexed
(TDM) scheme that divides each audio frame into 12 outgoing and 12 incoming data streams, each
with 20-bit sample resolution.
The STAC9766/9767 DACs, ADCs and SPDIF can be assigned to slots 3&4, 6&9, 7&8 or 10&11.
Figure 14. Bi-directional AC-link Frame with Slot Assignments
SLOTS
0 1 2 3 4 5 6 7 8 9 10 11 12
SYNC
OUTGOING STREAMS
(Controller output - SDATA_OUT)
INCOMING STREAMS
(codec output - SDATA_IN)
TAG PHASE
TAG
CMD CMD PCM
ADDR DATA LEFT
PCM
RT
NA
PCM PCM PCM
CTR LSURR RSURR
PCM
LFE
SPDIF
SPDIF
IO
CTRL
TAG
STATUS STATUS PCM
ADDR DATA LEFT
PCM LINE1 PCM Vendor Vendor Vendor LINE2 HSET
IO
RT
ADC MIC RSVD RSVD RSVD ADC ADC STATUS
DATA PHASE
Slot 12 can be used by the
AC'97 Codec if a Modem
Codec is not present.
Table 4. AC-link Output Slots (Transmitted from the Controller)
Slot
Name
Description
0 SDATA_OUT TAG
MSBs indicate which slots contain valid data; LSBs convey
CODEC ID
1 Control CMD ADDR write port Read/write command bit plus 7-bit CODEC register address
2 Control DATA write port
16-bit command register write data
3, 4 PCM L&R DAC playback
20-bit PCM data for Left and Right channels
5 Modem Line 1 DAC
16-bit modem data for modem Line 1 output
6, 7, 8, 9 PCM Center, Surround L&R, LFE 20-bit PCM data for Center, Surround L&R, LFE channels
10 Modem Line 2 DAC
16-bit modem data for modem Line 2 output
11 Modem handset DAC
16-bit modem data for modem Handset output
12 Modem IO control
GPIO write port for modem Control
12 CODEC IRQ
Can be used by CODEC if a modem CODEC is not present.
10-11 SPDIF Out
Optional AC-link bandwidth for SPDIF output
10-12 Double rate audio
Optional AC-link bandwidth for 88.26KHz or 96KHz on L, C, R
channels
IDT™
27
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH STEREO MICROPHONE AND MIC/JACK SENSING
STAC9766/9767
V 7.4 12/06