CS4235 Datasheet, PDF (52/94 Pages) Cirrus Logic – CrystalClear Low Cost ISA Audio System

CS4235
CrystalClear ^TM Low Cost ISA Audio System
DIN/EEN
ICH
When read (DIN), this bit reflects
the SDA pin, which should be serial
data output from the Plug and Play
E²PROM. EEN and DOUT must be
1 for this bit to function.
When written (EEN), enables the
E²PROM interface: CLK and DOUT
onto the SCL/SDA pins. Writing:
0 - E²PROM interface disabled
1 - E²PROM interface enabled
Interrupt polarity - CDROM. When set,
the CDINT pin is an active high sig-
nal. When low, CDINT is an active
low signal. This bits can be initial-
ized through the Hardware
Configuration data.
Block Power Down (X28)
Default = 00000000
D7 D6 D5 D4 D3 D2 D1 D0
PDWN SRC VREF MIX ADC1 DAC1 PROC FM
This register and CTRLbase+2 access the same
data. See CTRLbase+2 for a detailed description of
each bit.
Power Management (X29)
Default = 0xxxx000
D7 D6 D5 D4
RESET res res res
D3 D2 D1 D0
res MIXCD DAC2 SPORT
This register and C9 access the same data.
SPORT
Powers down the serial ports.
DAC2
Powers down DAC2 including FM and
the CS9236 serial interface.
MIXCD
Powers down the analog mixer - with
the exception of MIN, AUX2, and the
line outputs.
RESET
When this bit goes from a 1 to a 0, a
software RESDRV is initiated caus-
ing the entire chip to be reset and
placed in its default power-up con-
figuration. Access to all registers on
this chip will be lost, including this
one, since the power-up state for
PnP is all resources unassigned.
Global Status (X30)
CTRLbase+7, Default = 1000000x
D7 D6 D5 D4 D3 D2 D1 D0
CWSS ICTRL ISB IWSS IMPU WDT IMV res
X30 and CTRLbase+7 access the same data.
IMV
Hardware Master Volume Control
Interrupt Status. A hardware volume
control interrupt is pending when set
to 1. Master Volume Interrupts are
enabled through VCIE in C8/X24.
This bit can only be cleared through
CTRLbase+7, not X30.
WDT
Watch-Dog Timer. If an error occurs
on the ISA bus, the Processor will
be reset and WDT will be set.
IMPU
MPU-401 Interrupt status. MPU inter-
rupt pending when set to 1.
IWSS
Windows Sound System Interrupt
Status. WSS interrupt pending when
set to 1.
ISB
Sound Blaster Interrupt status. Sound
Blaster interrupt pending when set to
1.
ICTRL
Control Logical Device 2 Interrupt
status. A context switch interrupt is
pending when set to 1.
CWSS
Context - WSS. Indicates the current
context.
0 - Sound Blaster Emulation
1 - Windows Sound System
Reserved (X31)
Default = xxxxxxxx
D7 D6 D5 D4 D3 D2 D1 D0
res res res res res res res res
res
Reserved. Could read as 0 or 1.
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DS252PP2