CS4237B Datasheet, PDF (68/114 Pages) Cirrus Logic – CrystalClear Advanced Audio System with 3D Sound

CS4237B
CS9236 Wavetable Control (C8)
Default = xxxx0000
D7 D6 D5 D4 D3 D2 D1
res res res res WTEN SPS DMCLK
D0
BRES
BRES
Force BRESET low. When set, the
BRESET pin is forced low. Typically
used for power management of pe-
ripheral devices.
DMCLK
Disable MCLK. When set, the MCLK
pin of the CS9236 Wavetable Syn-
thesizer serial interface is forced low
providing a power savings mode.
SPS
WTEN
DSP Serial Port Switch. When set,
switches the DSP serial port pins
from the 2nd joystick to the XD4-
XD1 pins. When SPE in I16 is set,
XD4-XD1 convert to the DSP serial
port pins. Once SPS is enabled, the
SD<7:0> bus will not be driven when
accesses occur to peripheral port de-
vices. SPS can also be set in the
E²PROM Hardware Configuration
data, Global Configuration byte.
Wavetable Serial Port Enable. When,
set, forces XD7-XD5 pins to convert
to the CS9236 Single-Chip Wave-
table Music Synthesizer serial port
pins. Once WTEN is enabled, the
SD<7:0> bus will not be driven when
accesses occur to peripheral port de-
vices. WTEN can also be set in the
E²PROM Hardware Configuration
data, Global Configuration byte.
Setting this bit also changes I6/I7
from the master digital audio volume
to the ISA bus wave volume control.
X14/15 becomes the master digital
audio volume.
res
Reserved. Must write 0. Could read
as 0 or 1.
SRS 3D Sound Overview
The SRS 3D Stereo DSP engine is designed to
retrieve and restore spacial information, direc-
tional cues, and other sonic nuances which are
68
either missing or altered by the electronic repro-
duction of stereo and/or the microphone mixing
process. SRS 3D Mono processing, when used in
conjunction with the SRS 3D Stereo system,
synthesizes a 3D stereo signal from a monaural
source.
SRS stands for Sound Retrieval System. It dif-
fers from stereo and other sound expansion
techniques because it is based on the human
hearing system. The ears are complex instru-
ments that allow us to hear in three dimensions.
Microphones and traditional stereo playback sys-
tems only produce flat, two dimensional sound
images which are somewhat limited compared to
"real live sound". SRS compensates for these
limitations by re-establishing the necessary infor-
mation that allows us to hear in three
dimensions. The results are surprisingly close to
real live sound.
SRS is unique because it does not rely on special
recording techniques. It works with any audio
signal whether it is mono, stereo, surround
sound, or even signals encoded with a sound-en-
hancement process. Most importantly, SRS does
not alter the original program material by adding
any form of time delay, phase shift, or harmonic
distortion.
With SRS 3D sound there is no critical listening
position or sweet spot. The listener can move
around the room and continue to be immersed in
full three-dimensional sound. Speakers are no
longer the discernible point source of sound.
SRS is a patented process that differs from ste-
reo and surround sound in that it works with any
existing recorded material: mono, stereo, sur-
round-encoded, or other encoding technologies.
SRS is not required in the recording process.
This means a listener’s entire audio library can
be enhanced by SRS by simply playing it
through the CS4237B Crystal chip. Like stereo,
any two-speaker stereo system is adequate.
DS213PP4