CS4237B Datasheet, PDF (39/114 Pages) Cirrus Logic – CrystalClear Advanced Audio System with 3D Sound

0 - Mono
1 - Stereo
CEN
C/L, FMT1, and FMT0 bits set the audio data format
as shown below. In MODE 1, FMT1,
which is forced low, FMT0, and C/L
are used for both playback and cap-
ture. In MODEs 2 and 3, these bits
are only used for playback, and the
capture format is independently se-
lected via register I28. MCE (R0) or
PMCE (I16) must be set to modify
the upper four bits of this register.
See Changing Audio Data Formats
section for more details.
FMT1^†
D7
0
0
0
0
1
1
1
1
FMT0
D6
0
0
1
1
0
0
1
1
C/L
Audio Data Format
D5
0 _{Linear, 8-bit unsigned}
1 _{µ-Law, 8-bit companded}
0 _{Linear, 16-bit two’s}
complement, Little Endian
1 _{A-Law, 8-bit companded}
0 _RESERVED
1 _{ADPCM, 4-bit, IMA compatible}
0 _{Linear, 16-bit two’s}
complement, Big Endian
1 _RESERVED
† FMT1 is not available in MODE 1 (forced to 0).
Interface Configuration (I9)
Default = 00x01000
D7 D6 D5 D4 D3 D2 D1 D0
CPIO PPIO res CAL1 CAL0 SDC CEN PEN
PEN
Playback Enable. This bit enables
playback. The WSS Codec will
generate a DRQ and respond to
DACK signal when this bit is en-
abled and PPIO=0. If PPIO=1, PEN
enables PIO playback mode. PEN
may be set and reset without setting
the MCE bit.
0 - Playback Disabled (playback DRQ
and PIO inactive)
1 - Playback Enabled
SDC
CAL1,0
PPIO
CPIO
DS213PP4
CS4237B
Capture Enabled. This bit enables the
capture of data. The WSS Codec
will generate a DRQ and respond to
DACK signal when CEN is enabled
and CPIO=0. If CPIO=1, CEN en-
ables PIO capture mode. CEN may
be set and reset without setting the
MCE bit.
0 - Capture Disabled (capture DRQ
and PIO inactive)
1 - Capture Enabled
Single DMA Channel: This bit will force
BOTH capture and playback DMA re-
quests to occur on the Playback
DMA channel. This bit forces the
WSS Codec to use one DMA chan-
nel. Should both capture and
playback be enabled in this mode,
only the playback will occur. See the
DMA Interface section for further ex-
planation.
0 - Dual DMA channel mode
1 - Single DMA channel mode
Calibration: These bits determine
which type of calibration the WSS
Codec performs whenever the Mode
Change Enable (MCE) bit, R0,
changes from 1 to 0. The number of
sample periods required for calibra-
tion is listed in parenthesis.
0 - No calibration (0)
1 - Converter calibration (321)
2 - DAC calibration (120)
3 - Full calibration (450)
Playback PIO Enable: This bit deter-
mines whether the playback data is
transferred via DMA or PIO.
0 - DMA transfers
1 - PIO transfers
Capture PIO Enable: This bit deter-
mines whether the capture data is
transferred via DMA or PIO.
0 - DMA transfers
1 - PIO transfers
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