Specifications

ESS Technology, Inc. SAM0025A-062397 61
ES1879 DATA SHEET
PROGRAMMING THE ES1879
PRELIMINARY
Table 21 Mixer Input Volume Registers
Sound Blaster Pro Master Volume Emulation
Using Sound Blaster Pro emulation for master volume
means that the 6-bit volume counters can be written via
the Sound Blaster Pro Mixer register 22h (or 32h). Sound
Blaster Pro emulation is enabled by default, and can be
disabled by setting bit 0 of Mixer register 64h.
The master volume registers 60h and 62h can always be
read, regardless of whether Sound Blaster Pro volume
emulation is enabled, using the Sound Blaster Pro mixer
register 22h (or 32h). The following 6-bit to 4-bit translation
table is used:
If Sound Blaster Pro volume emulation is enabled, then a
mixer reset will cause both left and right channels to set to
their power-on default, namely 54 (or 36h).
If Sound Blaster Pro volume emulation is enabled, then a
write to mixer register 22h (or 32h) will cause both the left
and right master volume registers to be changed as
follows:
Mixer Input
Playback Volume
Register
Record Volume
Register
Audio 1 14h –
Audio 2 7Ch 69h
Microphone 1Ah 68h
Music DAC (FM/
689/69x)
36h 6Bh
AuxA (CD) 38h 6Ah
AuxB 3Ah 6Ch
Line 3Eh 6Eh
I
2
S
6Dh 6Fh
Table 22 SB Pro Read Volume Emulation
Mute Master Volume
Value Read
at 32h
Value Read
at 22h
1xx 0 1
0 0-24 1 1
025-3023
031-3433
035-3845
039-4255
043-4667
047-5077
051-5489
055 9 9
0 56-57 10 11
058 11 11
0 59-60 12 13
061 13 13
062 14 15
063 15 15
Table 23 SB Pro Write Volume Emulation
Value written to 22h or 32h Mute 6-bit Volume
0124
1024
2030
3034
4038
5042
6046
7050
8054
9055
10 0 56
11 0 58
12 0 59
13 0 61
14 0 62
15 0 63