ES1371 Datasheet, PDF (21/37 Pages) List of Unclassifed Manufacturers – ENSONIQ AudioPCI 97 digital controller

ENSONIQ Proprietary Information
7.5. CODEC Interface
The CODEC interface register is a 32 bit register that provides access to the AC97 CODEC control
registers. This register is a pseudo read/write and must be accessed as a longword. A write to this register
will initiate a CODEC register read/write operation. A read from this register is used to read a CODEC
register that was initiated by a previous write to the CODEC interface register.
CODEC Write Register
Addressable as longword
Power on reset value 00000000H
Bit(s) R/W Name
31:24 W ZERO
23
W PIRD
22:16 W
15:0 W
PIADD
PIDAT
Address 14H
Direct Mapped
Function
These bits are always zeros.
AC97 Codec register read/write control bit
0 - Write AC97 CODEC register.
1 - Read AC97 CODEC register.
These bits are the address of the AC97 CODEC register to be
read/written.
These bits are the data value to be written into the AC97 CODEC
register. Set to zero for a AC97 CODEC register read.
CODEC Read Register
Addressable as longword
Power on reset value 00000000H
Bit(s) R/W Name
31
R RDY
30
R WIP
29:24 R
23
R
ZERO
PORD
22:16 R
15:0 R
POADD
PODAT
Address 14H
Direct Mapped
Function
This bit when high indicates that this register contains valid read
data from the AC97 CODEC register file.
This bit when high indicates that a register read/write to the AC97
CODEC is in progress.
0 - AC97 CODEC register interface inactive.
1 - AC97 CODEC register access in progress.
These bits always read back as zeros.
AC97 Codec register read/write control bit
0 - Write AC97 CODEC register.
1 - Read AC97 CODEC register.
These bits are the address of the AC97 CODEC register for the read
register operation.
These bits are the data value read from the AC97 CODEC register
at the above address.
ENSONIQ Proprietary Information
ENSONIQ AudioPCI 97 Specification Rev 1.1 Oct 1, 1997
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