STAC9752 Datasheet, PDF (73/95 Pages) Integrated Device Technology – TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING

STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s) Reset Value Name
Description
4
1
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.
0 - 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.
IV
1 - 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
writing 1, 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#.
3-1
0
RESERVED Bits not used, should read back 0
0
NA
Function Information Present
FIP
This bit 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 22. 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 23. 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 24. Register 68h/Page 01h Bit Overview
Bit
D15:D5
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.
8.4.6.
Digital Audio Control (6Ah, Page 00h)
To access Register 6Ah, Page 00h must be selected in Register 24h.
IDT™
73
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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