Specifications

60 SAM0025A-062397 ESS Technology, Inc.
ES1879 DATA SHEET
PROGRAMMING THE ES1879
PRELIMINARY
Extended Access to ADC Source Select
In Sound Blaster Compatibility mode in the Sound Blaster
Pro mixer, there are three choices for recording source,
set by bits 2 and 1 of Mixer register 0Ch. Note that bit 0 is
set to 0 upon any write to 0Ch and set to 1 upon any read
from 0Ch:
For extended access, use register address 1Ch to select
recording from the mixer as follows:
NOTE:
Unless specifically stated, any of the above
sources may have audio from the ES978 mixed in.
In addition to mixer registers 0Ch and 1Ch, the ES1879
has a separate mixer register for selecting the record
source during DSP serial mode.
a.The master volume inputs are the outputs of
the Spatializer processor, before master vol-
ume is applied.
Record and Playback Mixer
The ES1879 has stereo mixers for record and playback.
Each stereo mixer has eight input sources, each with
independent 4-bit left and right volume controls, plus an
input source from the ES978. For each 4-bit volume
control, level 0 is mute and level 15 is maximum volume.
The ES1879 mixers use a dual-slope method for selecting
volume. Each increase of one step in volume from settings
1 to 8 results in a +3 dB increase. Each increase of one
step in volume from settings 8 to 15 results in a +1.5 dB
increase.
Extended Access Mixer Volume Values
a.Audio 1 DAC mixer input is gated by Sound
Blaster “Speaker On” control. This control bit is
toggled by the D1 (on) and D3 (off) Sound Blast-
er commands.
b.In Telegaming mode (enabled by bit 0 of mixer
register 48h when in serial mode), the audio 2
DAC mixer input volume is slaved to the audio 1
DAC mixer input volume.
c.Alternatively, the I
2
S DAC volume can be set by
the volume of the FM DAC at register 36h. This
is useful when the I
2
S interface is used for an ex-
ternal wavetable synthesizer. Bit 3 of Vendor-
Defined Card-Level register 2Bh when set high
will enable tracking with FM volume.
D2 D1 Source Selected
0 0 Microphone (default)
0 1 CD (Aux) input
1 0 Microphone
1 1 Line input
D2 D1 D0 Source Selected
0 0 0 Microphone (default)
0 0 1 Left channel: microphone (not mixed with
ES978 mic).
Right channel: master volume inputs
a
(left
and right).
0 1 0 CD (Aux) input
0 1 1 Left channel: AOUTL
Right channel: AOUTR
1 0 0 Microphone
1 0 1 Record mixer
1 1 0 Line input
111
Master volume inputs.
a
Volume in decibels (dB)
4-bit
Value
Audio 1
a
,
Audio 2
b
Mic,
Music DAC,
I
2
S
c
AuxA, AuxB,
Line
15 0 + 12.0 + 4.5
14 - 1.5 + 10.5 + 3.0
13 - 3.0 + 9.0 + 1.5
12 - 4.5 + 7.5 0
11 - 6.0 + 6.0 - 1.5
10 - 7.5 + 4.5 - 3.0
9 - 9.0 + 3.0 - 4.5
8 - 10.5 + 1.5 - 6.0
7 - 13.5 - 1.5 - 9.0
6 - 16.5 - 4.5 - 12.0
5 - 19.5 - 7.5 - 15.0
4 - 22.5 - 10.5 - 18.0
3 - 25.5 - 13.5 - 21.0
2 - 28.5 - 16.5 - 24.0
1 - 31.5 - 19.5 - 27.0
0 mute mute mute