STAC9752A Datasheet, PDF (77/106 Pages) Integrated Device Technology – AC’97 2.3 CODECS WITH STEREO MICROPHONE & UNIVERSAL JACK

STAC9752A/9753A
AC’97 2.3 CODECS WITH STEREO MICROPHONE & UNIVERSAL JACK
PC AUDIO
Bit(s) Reset Value Name
4
1
IV
3-1
0
Reserved
0
NA
FIP
Description
Information Valid Bit: Indicates whether a sensing method is provided by the
CODEC and if information field is valid. This field is updated by the CODEC.
0h--After CODEC RESET# de-assertion, it indicates the CODEC does NOT
provides sensing logic and this bit will be Read Only. After a sense cycle is
completed indicates that no information is provided on the sensing method.
1h--After CODEC RESET# de-assertion, it indicates the CODEC provides
sensing logic for this I/O and this bit is Read/Write. After clearing this bit by
writing1, when a sense cycle is completed the assertion of this bit indicates that
there is valid information in the remaining descriptor bits. Writing 0 to this bit has
no effect.
BIOS should NOT write this bit, as it is reset on RESET#.
Bit not used, should read back 0
Function Information Present
This bit is set to a 1 indicates that the G[4:0], INV, DL[4:0](Register 68h, Page
01h) and ST[2:0](register 6Ah, Page 01h) are supported and R/W capable.
This bit is Read Only.
Table 23. Reg 68h Default Values
Reg 66h Function Code
Reg 68h Default Value
00h Line Out
0010h
01h Headphone Out
0010h
05h Mic1
0010h
06h Mic2
0010h
All other Function Codes
0000h
For RESET#: Reg 68h default value is 0000h.
Table 24. Gain or Attenuation Examples
G[4:0]
00000
00001
01111
10001
11111
Gain or Attenuation (dB relative to level-out)
0 dBV
+1.5 dBV
+24 dBV
-1.5 dBV
-24 dBV
Table 25. Register 68h/Page 01h Bit Overview
Bit
D5:D15
D4
D3:1
D0
Bit R/W Overview
Read/Write and only reset on POR (Power on Reset) and not by RESET#.
Read/Write and should NOT be set by the BIOS
Reserved
Read Only.
7.4.6.
Digital Audio Control (6Ah, Page 00h)
To access Register 6Ah, Page 00h must be selected in Register 24h.
IDT™
77
AC’97 2.3 CODECS WITH STEREO MICROPHONE & UNIVERSAL JACK
STAC9752A/9753A
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