STAC9752 Datasheet, PDF (35/95 Pages) Integrated Device Technology – TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING

STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
5.3.3.
5.3.4.
5.3.5.
5.3.6.
5.3.7.
AC-Link output frame slot 1 communicates control register address, and write/read command infor-
mation to the STAC9752/9753.
Table 8. Command Address Port Bit Assignments
Bit
19
18:12
11:0
Description
Read/Write command
Control Register Index
Reserved
Comments
1= read, 0 = write
Sixty-four 16-bit locations, addressed on even byte boundaries
Stuffed with 0
The first bit (MSB) sampled by AC‘97 indicates whether the current control transaction is a read or a
write operation. The following 7 bit positions communicate the targeted control register address. The
trailing 12 bit positions within the slot are reserved and must be stuffed with 0 by the AC‘97 Control-
ler.
Slot 2: Command Data Port
The command data port is used to deliver 16-bit control register write data in the event that the cur-
rent command port operation is a write cycle (as indicated by Slot 1, bit 19).
• Bit(19:4) Control Register Write Data (Stuffed with 0 if current operation is a read)
• Bit(3:0) Reserved (Stuffed with 0)
If the current command port operation is a read then the entire slot time must be stuffed with 0 by the
AC‘97 Controller.
Slot 3: PCM Playback Left Channel
AC-Link output frame slot 3 is the composite digital audio left playback stream. In a typical “Games
Compatible” PC this slot is composed of standard PCM (.wav) output samples digitally mixed (on the
AC‘97 Controller or host processor) with music synthesis output samples. If a sample stream of res-
olution less than 20-bits is transferred, the AC‘97 Controller must stuff all trailing non-valid bit posi-
tions within this time slot with 0.
The DAC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
Slot 4: PCM Playback Right Channel
AC-Link output frame slot 4 is the composite digital audio right playback stream. In a typical “Games
Compatible” PC this slot is composed of standard PCM (.wav) output samples digitally mixed (on the
AC‘97 Controller or host processor) with music synthesis output samples. If a sample stream of res-
olution less than 20-bits is transferred, the AC‘97 Controller must stuff all trailing non-valid bit posi-
tions within this time slot with 0.
The DAC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
Slot 5: Modem Line 1 Output Channel
Audio output frame slot 5 is reserved for modem operation and is not used by the STAC9752/9753.
Slot 6 - 11: DAC
The DAC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
IDT™
35
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206