CS4235 Datasheet, PDF (55/94 Pages) Cirrus Logic – CrystalClear Low Cost ISA Audio System

CS4235
CrystalClear ^TM Low Cost ISA Audio System
Input Control Register,
Mixer Index 0CH
This register selects the input source to the ADC.
D2,D1 - 00 - Microphone
01 - CD Audio
10 - Microphone
11 - Line In
Output Control Register,
Mixer Index 0EH
VSTC - 0 - Mono Mode
1 - Stereo Mode
Master Volume Register,
Mixer Index 22H, Default = 99H
This register provides 8 steps of master volume
control each for the right and left channels.
FM Volume Register,
Mixer Index 26H, Default = 99H
This register provides 8 steps of FM volume
control each for the right and left channels.
CD Volume Register,
Mixer Index 28H, Default = 01H
This register provides 8 steps of CD volume
control each for the right and left channels.
Line-In Volume Register,
Mixer Index 2EH, Default = 01H
This register provides 8 steps of line-in volume
control each for the right and left channels.
GAME PORT INTERFACE
The Game Port logical device software interface
utilizes 10-bit address decoding and is located at
PnP address ’GAMEbase’. 10-bit addressing re-
quires that the upper address bits be 0 to decode
a valid address, i.e. no aliasing occurs. For back-
wards compatibility, the Game Port consists of 8
I/O locations where the lower 6 alias to the same
location, which consists of one read and one
write register.
Plug and Play configuration capability will allow
the joystick I/O base address, GAMEbase, to be
located anywhere within the host I/O address
space. Currently most games software assume
that the joystick I/O port is located at 200h.
A write to the GAMEbase register triggers four
timers. A read from the same register returns
four status bits corresponding to the joystick fire
buttons and four bits that correspond to the out-
put from the four timers.
A button value of 0 indicates the button is
pressed or active. The button default state is 1.
When GAMEbase is written, the X/Y timer bits
go high. Once GAMEbase is written, each timer
output remains high for a period of time deter-
mined by the current joystick position. The
number in parenthesis below is the joystick con-
nector pin number.
GAMEbase+0 - GAMEbase+7
D7 D6 D5 D4 D3 D2 D1 D0
JBB2 JBB1 JAB2 JAB1 JBCY JBCX JACY JACX
JACX
JACY
JBCX
JBCY
Joystick A, Coordinate X (pin 3)
Joystick A, Coordinate Y (pin 6)
Joystick B, Coordinate X (pin 11)
Joystick B, Coordinate Y (pin 13)
JAB1
JAB2
JBB1
JBB2
Joystick A, Button 1 (pin 2)
Joystick A, Button 2 (pin 7)
Joystick B, Button 1 (pin 10)
Joystick B, Button 2 (pin 14)
DS252PP2
55