Specifications

66 SAM0025A-062397 ESS Technology, Inc.
ES1879 DATA SHEET
REGISTERS
PRELIMINARY
PC Speaker Volume (3Ch, R/W)
This register controls the PC speaker volume. Bits 2:0
select the attenuation level in steps of -3 dB. The
maximum setting of 08h corresponds to 0 dB attenuation.
On reset, this register assumes the value of 04h.
Line Volume (3Eh, R/W)
This registers controls the playback volume of the line
input. On reset, this register assumes the value of 00h.
ES1879 Identification Value (40h, R)
To identify the ES1879, mixer register 40h returns the
following values on four successive reads:
18h, 79h, A[11:8], A[7:0]
where 18h and 79h are data reads indicating the part
number (1879) and A[11:0] is the base address of the
configuration device.
Serial Interface Registers
This section describes registers related to the DSP and
ES689/ES69x serial interface.
Serial Mode Input Control (42h, R/W)
This register can be used to gain independent control of
the record source and record volume, while in serial mode.
When in serial mode, mixer registers 0Ch/1Ch and
controller register B4h can still be used to control record
source and record volume if desired. Mixer register 42h
enables the ES1879 to have two different values set for
record source and record volume dependent on whether
the ES1879 is in serial mode or not. This register only
takes control of record source and volume while the
ES1879 is in serial mode and bit 7 is high.
Bits Definitions:
PC speaker volume
76543210
Line volume left Line volume right
76543210
ES1879 identification value
7 6543210
Input
override
Record source Record volume
76543210
Bits Name Description
7 Input
override
1 = Input source and input volume replace nor-
mal values as programmed by the application
when the ES1879 is in serial mode.
0 = Input source and input volume are
unchanged during serial mode.
6:4 Record
source
Record source selects the record source dur-
ing serial mode if bit 7 is high. The values
below override the normal mixer settings (reg-
ister 0Ch or 1Ch):
bit 6
bit 5 bit 4 record source selected
0 0 0 Microphone (default).
0 0 1 CD (AuxA) input.
0 1 0 Microphone.
1 0 0 Left channel: mic (not mixed
with ES978 mic).
Right channel: master vol-
ume inputs (left + right).
1 0 1 Left channel: AOUTL
Right channel: AOUTR.
1 1 0 Record mixer.
1 1 1 Record source discon-
nected from filters
(muted). Record source
is unchanged in serial
mode.
3:0 Record
volume
If bit 7 is high during serial mode, this value
overrides the record volume settings set via
controller register B4h. For microphone
source, the record gain is from 0 to +22 dB in
steps of 1.5 dB. For other sources, the record
gain is from -6 to +16.5 dB in steps of 1.5 dB.