Specifications

ESS Technology, Inc. SAM0025A-062397 9
ES1879 DATA SHEET
FUNCTIONAL DESCRIPTION
PRELIMINARY

ESFM
™
music synthesizer
– high-quality OPL3
superset FM synthesizer.

3-D Processor
– Spatializer technology 3-D audio effects
processor.

Hardware volume control
– three pushbutton inputs
with internal pull-up devices for up/down/mute can be
used to adjust the master volume control.
The state of these pins is logically AND’d with the state
of the corresponding pins of the ES978 when docked.
A software-selectable option allows the mute input to
be omitted. The mute input is defined as the state when
both up and down inputs are low. By default, this
feature is disabled.
The hardware volume inputs of the ES1879 can be
used as general-purpose inputs (see bits 4 and 5 of
Vendor-Defined Card-Level register 25h). They cannot
be used as volume control inputs.
Analo
g
Subsystems

Stereo programmable record and playback mixers
–
seven input stereo mixers. Each input has independent
left and right 4-bit volume control.
– Line In
–Mic In
– Aux A (CD)
– Aux B (or FDXI)
– Digital audio (wave files)
– FM/ES689/ES69x music DAC
–I
2
S serial port DAC

16-Bit stereo CODEC
– for audio record and playback
CODEC.

16-Bit stereo system DAC
– for audio playback of the
second audio channel.

16-Bit stereo music DAC
– for
ESFM
™ or external
wavetable synthesizer.

16-Bit Stereo I
2
S DAC
– I
2
S Zoom Video for MPEG audio
DAC.

1-Bit DAC
– for PC speaker digital input.

Recording source and input volume control
– input
source and volume control for record. The recording
source can be selected from one of seven choices:
–Mic
–Line
– Aux A (CD)
– Record Mixer
– Playback Mixer – master volume inputs (outputs of
the Spatializer processor, but before master volume
is applied).
– Playback Mixer – AOUT_L/AOUT_R (after master
volume has been applied).
– Mic/master volume inputs mix. Left channel: Mic
(not mixed with ES978 mic), Right channel: master
volume inputs left and right.
In any of the first four cases, the selected recording
source may be mixed with audio from the ES978 if the
selected source is also enabled in the ES978 and the
two chips are docked.

Master volume and mute control
– the master volume
is controlled by either Programmed I/O or volume control
switch inputs. The master volume supports 6 bits per
channel plus mute. When docked, the ES1879 first
transmits the master volume information to the ES978
mixer before it can take effect.

ES978 analog interface
– allows support for ES978
Expansion Audio Mixer in the docking station. The four-
wire differential analog bus carries audio data between
the ES978 and the ES1879. Audio data from the ES978
is input to the mixer of the ES1879. A switch determines
whether audio data transmitted to the ES978 is taken
before or after master volume is applied.

Reference generator
– analog reference voltage
generator.

PC speaker volume control
– the PC speaker is
supported with a 1-bit DAC with volume control. The
analog output pin PCSPKO is intended to be externally
mixed at the external amplifier. PC speaker audio is not
transmitted to the ES978 through the expansion audio
interface (XA[3:0]). The ES1879 is designed to play PC
speaker audio through the speakers inherent to the
portable unit.

General-purpose I/O
– Seven general-purpose inputs
and outputs which can be slaved with the corresponding
pins of the ES978 Expansion Audio Mixer.

Filter
– switched capacitor low-pass filter.

Preamp
– 26 dB microphone preamplifier.