STAC9758 Datasheet, PDF (56/119 Pages) Integrated Device Technology – HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS

STAC9758/9759
HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS™
PC AUDIO
8.2.8.
Mono/Stereo Mic Volume (0Eh)
Mic is actually one of 6 possible stereo input sources selected by the MicMux (Reg 66h, Page 0, Bits
D2:D0). Each of these sources may be selected as mono Left, mono Right, stereo, or stereo L-R
swapped. Boosts of 10, 20, or 30dB are available to all inputs controlled by the microphone mux.
8.2.8.1. Mic Volume Register in Mono Mode (default mode for Reg 0Eh)
Enabled when Stereo Mic Enable Bit (STMICEN), Reg 72h, Page 0, Bit D0 = 0
Default: 8008h.
D15
ALLMute
D7
RESERVED
D14
D6
BOOSTEN
D13
D5
RESERVED
D12
D4
GN4
D11
RESERVED
D3
GN3
D10
D2
GN2
D9
D1
GN1
D8
D0
GN0
Bit(s) Reset Value R/W Name
Description
Mutes Left and Right Channel Mic
15
1
RW ALLMute 0 = no mute
1 = muted
14:8
0
RO RESERVED Bit not used, should read back 0
Mutes Right Channel independent of Left Channel
0 = unmute
1 = muted
7
0
RW
RMute
The SPLITMUTE bit (Reg 72, Page 0, Bit D6) and STMICEN bit (Reg 72,
Page 0, Bit D0) must both be set to 1 in order for the RMute bit to have an
effect on the sound.
The RMute bit is R/W. The RMute bit may be written and read regardless
of the state of the SPLITMUTE and STMICEN bits.
Works with MICGAINVAL (Register 6Eh, Bit D2)
BOOSTEN MICGAINVAL
6
0
RW BOOSTEN
0
0
0
= 0 dB
1
= 10 dB
1
0
= 20 dB
1
1
= 30 dB
5
0
RO RESERVED Bit not used, should read back 0
Mic Volume Control
00h = 00000b = +12.0 dB gain
01h = 00001b = +10.5 dB gain
4:0
08
RW GN<4:0> .....
08h = 01000b = 0.0 dB - unity gain (default)
.....
1Fh = 11111b = -34.5 dB attenuation
IDT™
56
HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS™
STAC9758/9759
V 1.2 1206