STAC9750 Datasheet, PDF (35/73 Pages) Integrated Device Technology – VALUE-LINE TWO-CHANNEL AC’97 CODECS

STAC9750/9751
VALUE-LINE TWO-CHANNEL AC’97 CODECS
PC AUDIO
6.5.1.
Reset (00h)
Default: 6990h
D15
D14
D13
D12
D11
D10
D9
D8
RSRVD4
SE4
SE3
SE2
SE1
SE0
ID9
ID8
D7
D6
D5
D4
D3
D2
D1
D0
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
Writing any value to this register performs a register reset, which causes all registers to revert to
their default values. Reading this register returns the ID code of the part.
6.5.2.
Play Master Volume Registers (Index 02h, 04h, and 06h)
These registers manage the output signal volumes. Register 02h controls the stereo LINE_OUT
master volume (both right and left channels), register 04h controls the Headphone Out master vol-
ume, and register 06h controls the MONO volume output. Each step corresponds to 1.5 dB. The
MSB of the register is the mute bit. When this bit is set to 1 the level for that channel is set at -∞ dB.
ML5 through ML0 is for left channel level, MR5 through MR0 is for the right channel and MM5
through MM0 is for the mono out channel. When bits D5 and D13 are set in any of these registers it
automatically writes all 1 to the next lower 5-bits.
The default value is 8000h for registers 02h, 04h, and 06h, which corresponds to 0 dB attenuation
with mute on.
Mute
0
0
1
Table 16. Play Master Volume Register
Mx5…Mx0
00 0000
01 1111
xx xxxx
Function
0dB Attenuation
46.5 Attenuation
∞ dB Attenuation
Range
Req.
Req.
Req.
6.5.2.1. Master Volume (02h)
Default: 8000h
Note: If optional bits D13 & D5 of register 02h are set to 1, then the corresponding attenuation is set to
46.5dB and the register reads will produce 1Fh as a value for this attenuation/gain block.
D15
D14
Mute
RSRVD
D7
D6
Reserved
D13
ML5
D5
MR5
D12
ML4
D4
MR4
D11
ML3
D3
MR3
D10
ML2
D2
MR2
D9
ML1
D1
MR1
D8
ML0
D0
MR0
6.5.2.2. Headphone Out Volume (04h)
Default: 8000h
IDT™
VALUE-LINE TWO-CHANNEL AC’97 CODECS
35
STAC9750/9751
V 5.8 103106