YMF744B
February 3, 1999
-38-
2-2-2. Sound Blaster Pro Mixer
The following shows the register map of the Mixer section of Sound Blaster Pro.
Address
b7
b6
b5
b4
b3
b2
b1
b0
Remark
00h
Reset
04h
Voice Volume L
"1"
Voice Volume R
"1"
0Ah
-
-
-
"1"
-
MIC Volume*
0Ch
-
-
Ifilter*
"1"
Input Source*
"1"
0Eh
-
-
Ofilter*
"1"
-
-
St. SW
"1"
22h
Master Volume L
"1"
Master Volume R
"1"
26h
MIDI Volume L
"1"
MIDI Volume R
"1"
28h
CD Volume L*
"1"
CD Volume R*
"1"
2Eh
Line Volume L*
"1"
Line Volume R*
"1"
SB Pro Mixer
F0h
SBPDA
-
-
-
SS
SM
SE
SBPDR
F1h
SCAN DATA
Suspend / Resume
F8h
-
-
-
-
-
-
-
SBI
IRQ Status
The registers marked with * exist, but do not function.
DS-1S does not have the circuit that corresponds to the SB Mixer. Therefore, the volume settings on the
SB Mixer are converted to the DSP coefficients of DS-1S or to AC’97 register values.
The conversion for each case is described below.
(1) SB Mixer
®
DSP
The volume of master, MIDI and Voice, are applied to this case.
When the SB register is set, a 14-bit coefficient value is determined from the following conversion table
and used as the DSP coefficient. The attenuation value of Master Volume, MIDI, and voice are summed
together to obtain the coefficient.
These volumes cannot be controlled from PCI Audio block.