8169 Datasheet, PDF (20/30 Pages) STMicroelectronics – DIGITAL AUDIO PROCESSOR WITH MULTICHANNEL DDX™

STA304A
12.0 REGISTER SUMMARY
12.1 Reset Register (add. 00h)
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
0
0
0
0
0
0
0
0
1
1
1
0
0
1
0
0
Writing any value to this register performs a register reset, which causes all registers to revert to their default
values. Reading this register returns 00E4h as it is the ID code of the part and its 3D Stereo Enhancement type
(See AC'97 revision 2.1 specification, section 6.3.1).
12.2 LR Volume Register (add. 02h)
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1
Mute ML6 ML5 ML4 ML3 ML2 ML1 ML0 X MR6 MR5 MR4 MR3 MR2 MR1
D0
MR0
This register manage the stereo (both right and left channels) output signal volumes. 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. ML6 through ML0 is for the left
channel level, MR6 through MR0 is for the right channel.
There are two options: in 'Full Compliance' operating mode (bit 0 in the CRA register, address 5Ah, is set to '0')
only 6 bits are active (Mx0 to Mx5) and each step corresponds to 1.5 dB. In 'Proprietary' mode (bit 0 in the CRA
register is set to '1') Mx0 to Mx6 can have the values between 0h to 68h (110 1000) and each step corresponds
to 1dB. Greater values are undefined.
The default value is 8000h (1000 0000 0000 0000), which corresponds to 0 dB attenuation with mute on.
Mute
0
0
0
1
Mx6…Mx0
x00 0000
x01 1111
x11 1111
xxx xxxx
'Full Compliance' Mode
Function
0 dB Attenuation
46.5dB Attenuation
94.5dB Attenuation
∞ dB Attenuation
Mute
0
0
0
0
0
0
0
0
0
0
0
1
Mx6…Mx0
000 0000
001 1111
011 1111
…
110 0001
110 0010
110 0011
110 0100
110 0101
110 0110
110 0111
110 1000
xxx xxxx
'Proprietary' Mode
Function
0 dB Attenuation
31dB Attenuation
63dB Attenuation
...
97dB Attenuation
99dB Attenuation
100dB Attenuation
102dB Attenuation
104dB Attenuation
107dB Attenuation
111dB Attenuation
∞ dB Attenuation
∞ dB Attenuation
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