STAC9758 Datasheet, PDF (42/119 Pages) Integrated Device Technology – HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS

STAC9758/9759
HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS™
PC AUDIO
5.5. AC-Link Interoperability Requirements and Recommendations
5.5.1.
“Atomic slot” Treatment of Slot 1 Address and Slot 2 Data
Command or Status Address and Data cannot be split across multiple AC-Link frames. The following
transactions require that valid Slot 1 Address and valid Slot 2 Data be treated as “atomic” (insepara-
ble) with Slot 0 Tag bits for Address and Data set accordingly (that is, both valid):
1. AC‘97 Digital Controller write commands to Primary CODECs
2. AC‘97 CODEC status responses
Whenever the AC‘97 Digital Controller addresses a Primary CODEC, or an AC‘97 CODEC responds
to a read command, Slot 0 Tag bits should always be set to indicate actual Slot 1 and Slot 2 data
validity.
Table 12. Primary CODEC Addressing: Slot 0 Tag Bits
Function
AC‘97 Digital Controller
Primary Read Frame N,
SDATA_OUT
AC‘97 Digital Controller
Primary WriteFrame N,
SDATA_OUT
AC‘97 CODEC Status Frame
N+1, SDATA_IN
Slot 0, bit 15
Slot 0, bit 14
Slot 0, bit 13 Slot 0, Bits 1-0
(Valid Frame) (Valid Slot 1 Address) (Valid Slot 2 Data) (CODEC ID)
1
1
0
00
1
1
1
1
1
00
1
00
5.6.
When the AC‘97 Digital Controller addresses a Secondary CODEC, the Slot 0 Tag bits for Address
and Data must be 0. A non-zero, 2-bit, CODEC ID in the LSBs of Slot 0 indicates a valid Read or
Write Address in Slot 1, and the Slot 1 R/W bit indicates presence or absence of valid Data in Slot 2.
Slot Assignments for Audio
Table 13. Secondary CODEC Addressing: Slot 0 Tag Bits
Function
AC‘97 Digital Controller
Secondary Read Frame N,
SDATA_OUT
AC‘97 Digital Controller
Secondary Write Frame N,
SDATA_OUT
AC‘97 CODEC Status Frame
N+1, SDATA_IN
Slot 0, bit 15
Slot 0, bit 14
Slot 0, bit 13 Slot 0, Bits 1-0
(Valid Frame) (Valid Slot 1 Address) (Valid Slot 2 Data) (CODEC ID)
1
0
0
01, 10, or 11
1
0
1
1
0
01, 10, or 11
1
00
IDT™
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HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS™
STAC9758/9759
V 1.2 1206