cs4239 Cirrus Logic, Inc., cs4239 Datasheet - Page 30

• Manufacturer Part Number: cs4239
• Description: Crystalclear? Ortable Isa Audio System Logic
• Manufacturer: Cirrus Logic, Inc.

ways set in register I28.) If both playback and
capture are enabled, the default will be playback.
SDC does not have any affect when using PIO
accesses.
Sound System Codec Register Interface
The Windows Sound System codec is mapped
via four locations. The I/O base address,
WSSbase, is determined by the Plug and Play
configuration. The WSSbase supports four direct
registers, shown in Table 3. The first two direct
registers are used to access 32 indirect registers
shown in Table 4. The Index Address register
(WSSbase+0) points to the indirect register that
is accessed through the Indexed Data register
(WSSbase+1).
This section describes all the direct and indirect
registers for the WSS Codec. Table 5 details a
summary of each bit in each register with Ta-
bles 6 through 10 illustrating the majority of
decoding needed when programming the WSS
logical device, and are included for reference.
When enabled, the WSS Codec default state is
defined as MODE 1. MODE 1 is backwards
compatible with the CS4248 and only allows ac-
cess to the first 16 indirect registers. Putting the
part in MODE 2 or MODE 3, using CMS1,0 bits
in the MODE and ID register (I12), allows ac-
cess to indirect registers 16 through 31. Putting
the part in MODE 3 also allows access to the
extended registers through I23 and other ex-
tended features in the indirect registers.
30
Direct Registers: (R0-R3)
WSSbase+0
WSSbase+1
WSSbase+2
WSSbase+3
Index
Address
I10
I12
I13
I14
I15
I16
I17
I18
I19
I20
I21
I22
I23
I24
I25
I26
I27
I28
I29
I30
I31
I11
I0
I1
I2
I3
I4
I5
I6
I7
I8
I9
Table 4. WSS Codec Indirect Registers
CrystalClear Portable ISA Audio System
Table 3. WSS Codec Direct Register
Register Name
Left Analog Loopback
Right Analog Loopback
Left Aux #1 Volume
Right Aux #1Volume
Left Aux #2 Volume
Right Aux #2 Volume
Left DAC1 Volume
Right DAC1 Volume
Fs & Playback Data Format
Interface Configuration
Pin Control
Error Status and Initialization
MODE and ID
Reserved
Playback Upper Base Count
Playback Lower Base Count
Alternate Feature Enable I
Alternate Feature Enable II
Left DAC2 Volume
Right DAC2 Volume
Control/RAM Access
RAM Access End
Alternate Sample Frequency
Extended Register Access (X regs)
Alternate Feature Status
Compatibility ID
Mono Input Control
Left Master Output Volume
Capture Data Format
Right Master Output Volume
Capture Upper Base Count
Capture Lower Base Count
Reg.
R0
R1
R2
R3
TM
Index Address register
Indexed Data register
Status register
PIO Data register
Register Name
CS4239
DS253PP2