Audio Codec '97

AC ‘97 Component Specification Revision 2.3 Rev 1.0
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5.8.6 Vendor Reserved Registers (Index 5Ah - 5Fh, 70h - 7Ah)
Reg Name D15 D14 D13 D12 D11 D10 D9 D8 D7
D6
D5
D4
D3 D2 D1 D0 Default
5Ah-5Fh,
70hh-7Ah
Vendor Reserved X X X X X X X X X X X X X X X X X
These are reserved for vendor specific use. Driver writers should not access these registers unless the Vendor ID
register has been checked first to ensure that the vendor of the AC ‘97 component has been identified.
5.8.7 Extended Codec Registers Page Structure Definition
Reg PG ID Name D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 Default
60h-
6Eh
01h Register Name D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 na
Bit Default Function
D[15:0] na Extended Codec Registers Bits: These register allow for the definition of further
capabilities from those found in previous AC ’97 definitions.
Table 34. Extended Codec Registers bits definition
These bits provide a paged address space for extended codec information. The Page Selector bits in the Audio
Interrupt and Paging register (Register 24h bits 3:0) control the page of information viewed through this page
window.
5.8.7.1 Extended Registers Page 00
Page 00 of the Extended Codec Registers is reserved for vendor specific use. Driver writers should not access these
registers unless the Vendor ID register has been checked first to ensure that the vendor of the AC ‘97 component has
been identified and the usage of the vendor defined registers is understood.
5.8.7.2 Extended Registers Page 01
The usage Page 01 of the Extended Codec Registers is defined in section 5.9.
5.8.7.3 Extended Registers Page 02-0Fh
Pages 02 through 0Fh of the Extended Codec Registers are reserved for future use, and are not to be used by codec
hardware vendors or driver writers.
5.8.8 Vendor ID Registers (Index 7Ch - 7Eh)
Reg Name D15 D14 D13 D12 D11 D10 D9 D8 D7
D6
D5
D4
D3 D2 D1 D0 Default
7Ch Vendor ID1 F7 F6 F5 F4 F3 F2 F1 F0 S7 S6 S5 S4 S3 S2 S1 S0 na
7Eh Vendor ID2 T7 T6 T5 T4 T3 T2 T1 T0 DEV7 DEV6 DEV5 DEV4 DEV3 DEV2 DEV1 DEV0 na
All AC ‘97 Codecs are required to implement specific vendor identification, and this is essential for riser card
identification. The ID method is Microsoft’s Plug and Play Vendor ID code with F7..0 being the first character of
that ID, S7..0 being the second character and T7..0 the third character. These three characters are ASCII encoded.
The DEV[7:0] field allows for a vendor specific Device ID number for the specific codec.