STAC9721 Datasheet, PDF (28/48 Pages) List of Unclassifed Manufacturers – Stereo AC 97 Codec With Multi-Codec Option

SigmaTel, Inc.
Data Sheet
STAC9721
External
Pins
CID1, CID0
CID1 = DVdd
or floating,
CID0 = DVdd
or floating
CID1 = DVdd
or floating,
CID0 = GND
CID1 = GND,
CID0 = DVdd
or floating
CID1 = GND,
CID0 = GND
Table 19. Multi-Channel Programming Register
Extended
Audio ID
28h
ID1, ID0
0, 0
0, 1
1, 0
1, 1
Codec
Designation
Primary, 00
Secondary, 01
Secondary, 10
Secondary, 11
Multi-
Channel
Selection
74h
MC1, MC0
0, 0
0, 1
1, 0
1, 1
0, 0
0, 1
1, 0
1, 1
0, 0
0, 1
1, 0
1, 1
0, 0
0, 1
1, 0
1, 1
PCM
OUT Left
Slot 3
Slot 7
Slot 6
Slot 10
Slot 3
Slot 7
Slot 6
Slot 10
Slot 7
Slot 3
Slot 10
Slot 6
Slot 6
Slot 10
Slot 3
Slot 7
PCM
OUT
Right
Slot 4
Slot 8
Slot 9
Slot 11
Slot 4
Slot 8
Slot 9
Slot 11
Slot 8
Slot 4
Slot 11
Slot 9
Slot 9
Slot 11
Slot 4
Slot 8
4.4.14 Clock Access (Index 76h and 78h)
The Clock Access register (index 78h) is a locked register and can only be properly
written and read from when ABBAh has been written into register 76h. The
STAC9744/45 can operate as a remotely located secondary without a 24.576MHz master
clock input or local crystal. The STAC9744/45 can synchronize to the BIT_CLK after a
register adjustments. The first adjustment starts the synchronization process by enabling
the ALTCLK D13, PWD CL2x D12, CLK INV D11, and OSC PWD D1 bits of register
78h. With this adjustment, the STAC9744/45 will operate remotely without the 24.576
MHz master clock signal and without a local crystal. The XTAL_IN input should be
connected to DGND with a 10kΩ or larger resistor. The reserved bits of register 78h
should not be written to.
4.4.15 Vendor ID1 and ID2 (Index 7Ch and 7Eh)
These two registers contain four 8-bit ID codes. The first three codes have been assigned
by Microsoft using their Plug and Play Vendor ID methodology. The fourth code is a
SigmaTel, Inc. assigned code identifying the STAC9721/23. The ID1 register (index
7Ch) contains the value 8384h, which is the first (83h) and second (84h) characters of the
Microsoft^ ID code. The ID2 register (index 7Eh) contains the value 7609h, which is the
third (76h) of the Microsoft^ ID code, and 09h which is the STAC9721/23 ID code.
NOTE: The lower half of the Vendor ID2 register (index 7Eh) currently contains the
value 09h identifying the STAC9721/23. This value can be used by the audio driver, or
miniport driver in the case of WIN98^, to adjust software functionality to match the
feature-set of the STAC9721/23. This portion of the register will likely contain different
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04/07/00
04/07/00