YMF724F
2-2-2. Sound Blaster Pro Mixer
The following shows the register map of the Mixer section of Sound Blaster Pro.
Address
00h
b7
b6
b5
b4
b3
b2
b1
b0
Remark
Reset
04h
Voice Volume L
-
"1"
"1"
"1"
"1"
"1"
"1"
"1"
"1"
-
Voice Volume R
"1"
0Ah
0Ch
0Eh
22h
-
-
-
-
-
-
MIC Volume*
Input Source*
St. SW
Ifilter*
-
-
"1"
"1"
Ofilter*
-
SB Pro Mixer
Master Volume L
MIDI Volume L
CD Volume L*
Line Volume L*
Master Volume R
MIDI Volume R
CD Volume R*
Line Volume R*
"1"
26h
"1"
28h
"1"
2Eh
F0h
F1h
F8h
"1"
SBPDA
-
-
-
SS
SM
SE
SBPDR
Suspend / Resume
IRQ Status
SCAN DATA
-
-
-
-
-
-
SBI
The registers marked with * exist, but do not function.
DS-1 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-1 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.
January 14, 1999
-33-
YAMAHA [ YAMAHA CORPORATION ]
