Copyright
Cirrus Logic, Inc. 1997
(All Rights Reserved)
CS4235
Advanced Product Databook
CrystalClearTM
Low Cost ISA Audio System
FEATURES
s
Compatible with Sound BlasterTM, Sound Blaster
ProTM, and Windows Sound SystemTM
s
Advanced MPC3-Compliant Input and Output
Mixer
s
Enhanced Stereo Full Duplex Operation
s
Dual Type-F DMA Support
s
Integrated CrystalClearTM 3D Stereo
Enhancement
s
Industry Leading Delta-Sigma Data Converters
(86 dB FS A)
s
Internal Default PnP Resources
s
CS9236 Wavetable Interface
s
CS4610 Audio Accelerator Interface
s
CS4236B/CS4237B/CS4238B Register
Compatible
DESCRIPTION
The CS4235 is a single chip multimedia audio system
that is pin-compatible to the CS423xB for many de-
signs. The product includes an integrated FM
synthesizer and a Plug-and-Play interface. In addition,
the CS4235 includes hardware master volume control
pins as well as extensive power management and 3D
sound technology. The CS4235 is compatible with the
Microsoft
Windows Sound System standard and will
run software written to the Sound Blaster and Sound
Blaster Pro interfaces. The CS4235 is fully compliant
with Microsoft's PC'97 and PC'98 audio requirements.
ORDERING INFO
CS4235-JQ
100 pin TQFP, 14x14x1.4mm
CS4235-KQ
100 pin TQFP, 14x14x1.4mm
GAIN
GAIN
GAIN
ATTN
L/RAUX1
L/RAUX2
MIC
MIN
ATTN
OSCILLATOR
VREF
CMAUX2
L/ROUT
INPUT MIXER
OUTPUT MIXER
VREF
XTALI
XTALO
ISA
BUS
INTERFACE
PLUG
AND
PLAY
CODEC
REG
I/F
Config
IO
IRQ
DMA
CD-ROM or
Upper Address Bits
Decode
Logic
DACK<A:C>
DRQ<A:C>
IRQ<A:G>
IOCHRDY
AEN
IOW
IOR
SA<11:0>
SD<7:0>
FM
Synthesizer
ANALOG
JOYSTICK
LOGIC
MPU-401
UART
with
FIFOS
WSS
SBPRO
Registers
EEPROM
Interface
SDA
SCL
JOYSTICK
MIDI
BRESET
Stereo
DAC2
CS9236
WAVETABLE
INTERFACE
SA<12:15)
(CDROM)
SERIAL PORT
Stereo
ADC1
3D
Enhancement
FIFO
Stereo
DAC1
SERIAL PORT
CS4610
INTERFACE
FIFO
Hardware
Volume Control
UP
DOWN
MUTE
NOV `97
DS252PP2
TABLE OF CONTENTS
CS4235 PERFORMANCE SPECIFICATIONS ... 3
GENERAL DESCRIPTION ................................. 12
ISA Bus Interface............................................. 13
PLUG AND PLAY ............................................... 15
PnP Data ......................................................... 16
Loading Resource Data................................... 16
Loading Firmware Patch Data......................... 18
The Crystal Key ............................................... 18
Bypassing Plug and Play................................. 19
Crystal Key 2 ................................................... 20
Hardware Configuration Data .......................... 20
Hostload Procedure ......................................... 24
External E
2
PROM............................................ 25
WINDOWS SOUND SYSTEM CODEC .............. 26
Enhanced Functions (MODEs)........................ 27
FIFOs ............................................................... 27
WSS Codec PIO Register Interface ................ 27
DMA Interface.................................................. 28
Sound System Codec Register Interface ........ 29
Direct Mapped Registers (R0-R3) ............... 30
I/O Data Registers (R3) ............................... 31
Indirect Mapped Registers (I0-I31) .............. 32
WSS Extended Registers (X0-X31) ............ 44
SOUND BLASTER INTERFACE........................ 53
Mode Switching ............................................... 53
Sound Blaster Direct Register Interface.......... 53
Sound Blaster Mixer Registers........................ 54
GAME PORT INTERFACE ................................. 55
CONTROL INTERFACE ..................................... 57
Control Register Interface................................ 57
Control Indirect Registers (C0-C9) .................. 59
MPU-401 INTERFACE ........................................ 62
MPU-401 Register Interface ............................ 62
MIDI UART ...................................................... 63
MPU-401 "UART" Mode Operation ................. 63
FM SYNTHESIZER ............................................. 63
CDROM INTERFACE ......................................... 64
CS4610 DSP SERIAL DATA PORT .................. 64
CS9236 WAVETABLE SERIAL DATA PORT ... 66
WSS CODEC SOFTWARE DESCRIPTION .......67
Calibration ........................................................67
Changing Sampling Rate .................................68
Changing Audio Data Formats.........................69
Audio Data Formats .........................................69
DMA Registers .................................................69
WSS Codec Interrupt .......................................71
Error Conditions ...............................................71
DIGITAL HARDWARE DESCRIPTION...............72
Bus Interface ....................................................72
Volume Control Interface .................................72
Crystal/Clock ....................................................73
General Purpose Output Pins ..........................73
Reset and Power Down ...................................73
Address Port Configuration ..............................73
Multiplexed Pin Configuration ..........................74
ANALOG HARDWARE DESCRIPTION .............74
Line-Level Inputs Plus MPC Mixer...................74
Microphone Level Input ....................................75
Mono Input .......................................................75
Line-Level Outputs ...........................................75
Miscellaneous Analog Signals .........................76
GROUNDING AND LAYOUT ..............................76
POWER SUPPLIES.............................................76
ADC/DAC FILTER RESPONSE..........................78
PIN DESCRIPTIONS ...........................................80
ISA Bus Interface Pins .....................................81
Analog Inputs ...................................................82
Analog Outputs.................................................83
MIDI Interface...................................................84
External Peripheral Signals..............................84
Joystick Interface..............................................85
CS4610 DSP Serial Port Interface...................85
CS9236 Wavetable Serial Port Interface .........85
CDROM Interface.............................................86
Volume Control.................................................87
Miscellaneous...................................................87
Power Supplies ................................................88
PARAMETER DEFINITIONS...............................89
PACKAGE PARAMETERS .................................90
APPENDIX A: DEFAULT PnP DATA.................91
APPENDIX B: CS4235 DIFFERENCES .............93
CRD4235-8
CrystalClear 16-Bit Audio Motherboard Example Design
TM
DS252PP2
Windows 95 and Windows 3.1 are trademarks; Microsoft, Windows and Windows Sound System are registered
trademarks of Microsoft Corporation.
Sound Blaster and Sound Blaster Pro are trademarks of Creative Labs.
Ad Lib is a trademark of Adlib Corporation.
CrystalClear is a trademark of Cirrus Logic, Inc.
2
ANALOG CHARACTERISTICS
(T
A
= 25 C; VA, VD1, VDF1-VDF3 = +5 V;
Input Levels: Logic 0 = 0 V, Logic 1 = VD1; 1 kHz Input Sine wave; Sample Frequency, Fs = 44.1 kHz;
Measurement Bandwidth is 20 Hz to 20 kHz, 16-bit linear coding.)
CS4235-JQ
CS4235-KQ
Parameter*
Symbol Min
Typ
Max
Min
Typ
Max
Units
Analog Input Characteristics (A-D-PC) - Volume set to 0 dB unless otherwise specified.
ADC1 Resolution
(Note 1)
16
-
-
16
-
-
Bits
ADC1 Differential Nonlinearity
(Note 1)
-
-
0.5
-
-
0.5
LSB
Frequency Response:
Ac =
1 dB
FR
-
-
-
20
19000
Hz
Dynamic Range
AUX1, AUX2
(Note 2) MIC
DR
-
-
-80
-75
-
-
-80
-72
-85
-80
-
-
dB FS A
dB FS A
Total Harmonic Distortion+Noise AUX1, AUX2
-3 dB FS input
(Note 2) MIC
THD+N
-
-
-66
-66
-
-
-75
-72
-80
-80
-
-
dB FS A
dB FS A
Interchannel Isolation (Note 1):
Left to Right
10 kHz input
AUX1/2 to MIC
AUX1 to AUX2
-
-
-
-80
-80
-80
-
-
-
-70
-
-
-80
-80
-90
-
-
-
dB
dB
dB
Interchannel Gain Mismatch
AUX1, AUX2
MIC
-
-
-
-
0.5
0.5
-
-
-
-
0.5
0.5
dB
dB
ADC1 Offset Error
0 dB Gain
-
-
-
-
10
200
LSB
Full Scale Input Voltage:
(MGE/MBST=1) MIC
(MGE/MBST=0) MIC
AUX1, AUX2, MIN
0.25
2.5
2.5
0.28
2.8
2.8
-
-
-
0.25
2.5
2.5
0.28
2.8
2.8
-
-
-
V
pp
V
pp
V
pp
Gain Drift
-
100
-
-
100
-
ppm/C
Input Resistance (Note 1):
MIC
AUX1, AUX2, MIN
8
20
11
23
-
-
8
20
11
23
-
-
k
k
Input Capacitance
(Note 1)
-
-
15
-
-
15
pF
Notes:
1. This specification is guaranteed by characterization, no production testing.
2. MGE or MBST = 1 (see WSS Indirect Reg I0 or X2).
*Parameter definitions are given at the end of this data sheet.
Specifications are subject to change without notice.
CrystalClear Low Cost ISA Audio System
TM
CS4235
DS252PP2
3
ANALOG CHARACTERISTICS
(Continued)
CS4235-JQ
CS4235-KQ
Parameter*
Symbol
Min
Typ
Max
Min
Typ
Max
Units
Analog Output Characteristics (PC-D-A) - Volume set to 0 dB unless otherwise specified.
DAC1 Resolution
(Note 1)
16
-
-
16
-
-
Bits
DAC1 Differential Nonlinearity
(Note 1)
-
-
0.5
-
-
0.5
LSB
DAC1 Frequency Response:
Ac =
1 dB
FR
-
-
-
20
-
19000
Hz
DAC1 Dynamic Range
DR
-
-86
-
-80
-86
-
dB FS A
DAC1 Total Harmonic Distortion+Noise:
-3 dB FS input
(Note 3)
THD+N
-
-80
-
-74
-80
-
dB FS A
DAC1 Interchannel Isolation
(Notes 1,3)
-
-95
-
-80
-95
-
dB
DAC1 Interchannel Gain Mismatch
-
0.1
0.5
-
0.1
0.5
dB
Voltage Reference Output - VREF
2.0
2.2
2.5
2.0
2.2
2.5
V
Voltage Reference Output Current - VREF
(Notes 1,4)
-
100
400
-
100
400
A
DAC1 Programmable Attenuation Span
90
94.5
-
90
94.5
-
dB
DAC1 Atten. Step Size: Greater than -82.5 dB
-82.5 dB to -94.5 dB
1.3
1.0
1.5
1.5
1.7
2
1.3
1.0
1.5
1.5
1.7
2
dB
dB
DAC1 Offset Voltage
-
-
-
-
1
10
mV
Full Scale Output Voltage
(Note 3)
2.5
2.8
3.3
2.5
2.8
3.3
Vpp
Gain Drift
(Note 1)
-
100
-
-
100
-
ppm/C
Deviation from Linear Phase
(Note 1)
(Passband)
-
-
1
-
-
1
Degree
External Load Impedance
(Note 1)
10
-
-
10
-
-
k
Mute Attenuation
(Note 1)
80
-
-
80
-
-
dB
Power Supply
Power Supply Current
Digital, Operating
Analog, Operating
Total Operating
Total Power Down
-
-
-
-
70
30
100
-
-
-
-
-
-
-
-
-
70
30
100
-
80
35
-
1
mA
mA
mA
mA
Power Supply Rejection, 1 kHz
(Note 1)
40
-
-
40
-
-
dB
Notes:
3. 10 k
, 100 pF load.
4. DC current only. If dynamic loading exists, then the voltage reference output must be buffered
or the performance of ADCs and DACs will be degraded.
CrystalClear Low Cost ISA Audio System
TM
CS4235
4
DS252PP2
ABSOLUTE MAXIMUM RATINGS
(AGND, DGND, SGND = 0 V, all voltages with respect to 0 V.)
Parameter
Symbol
Min
Max
Units
Power Supplies:
Digital
Analog
VD1
VDF1-VDF3
VA
-0.3
-0.3
-0.3
6.0
6.0
6.0
V
V
V
Total Power Dissipation
(Supplies, Inputs, Outputs)
-
1
W
Input Current per Pin
(Except Supply Pins)
-10.0
+10.0
mA
Output Current per Pin
(Except Supply Pins)
-50
+50
mA
Analog Input Voltage
-0.3
VA+0.3
V
Digital Input Voltage:
SA<15:0>, IOR, IOW, AEN
SD<7:0>, DACK<A:C>
All other digital inputs
-0.3
-0.3
VD1+0.3
VDF+0.3
V
V
Ambient Temperature
(Power Applied)
-55
+125
C
Storage Temperature
-65
+150
C
Warning:
Operation beyond these limits may result in permanent damage to the device.
Normal operation is not guaranteed at these extremes.
MIXERS
(T
A
= 25 C; VA, VD1, VDF1-VDF3 = +5 V; Input Levels: Logic 0 = 0 V, Logic 1 = VD1;
1 kHz Input Sine wave, Measurement Bandwidth is 20 Hz to 20 kHz.)
CS4235-JQ
CS4235-KQ
Parameter*
Symbol Min Typ Max
Min
Typ
Max
Units
Mixer Gain Range Span
AUX1, AUX2
MIC
Hardware Master
DAC1, DAC2
-
-
-
-
-
-
-
-
-
42
40
75
85
45
45
86
94.5
-
-
-
-
dB
dB
dB
dB
Step Size
MIC, AUX1, AUX2
Hardware Master
DAC1, DAC2
-
-
-
-
-
-
-
-
-
1.3
1.6
0.9
1.5
2.0
1.5
1.7
2.4
2.0
dB
dB
dB
Frequency Response:
Ac =
1 dB
(Notes 1,3)
(A-A)
FR
-
-
-
20
-
20000
Hz
Dynamic Range
(Notes 1,3)
(A-A)
DR
-
-88
-
-90
-97
-
dB FS A
Total Harmonic Distortion+Noise
(Notes 1,3)
(A-A)
-3 dB FS input
THD+N
-
-85
-
-85
-90
-
dB FS A
CrystalClear Low Cost ISA Audio System
TM
CS4235
DS252PP2
5
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