DS632F1
27
CS44800
4.4
FsIn Clock Domain Modules
4.4.1
Digital Audio Input Port
The CS44800 interfaces to an external Digital Audio Processor via the Digital Audio Input serial port, the
DAI serial port. The DAI port has
4
stereo data inputs with support for I²S, left-justified and right-justified
formats. The DAI port operates in slave operation only, where DAI_LRCK, DAI_SCLK and DAI_MCLK are
always inputs. The signal DAI_LRCK must be equal to the sample rate, Fs and must be synchronously
derived from the supplied master clock, DAI_MCLK. The serial bit clock, DAI_SCLK, is used to sample
the data bits and must be synchronously derived from the master clock.
DAI_SDIN1, DAI_SDIN2, DAI_SDIN3, and DAI_SDIN4 are the serial data input pins supplying the asso-
ciated internal PWM channel modulators. The serial data interface format selection (left-justified, right-jus-
tified, I²S, one line mode, or TDM) for the DAI serial port data input pins is configured using the appropriate
bits in the register
“Misc. Configuration (address 04h)” on page 52
. The serial audio data is presented in
2's complement binary form with the MSB first in all formats.
When operated in One Line Data Mode, 6 channels of PWM data are input on DAI_SDIN1 and two addi-
tional PWM channels on DAI_SDIN4. In TDM mode, all
8
channels are multiplexed onto the DAI_SDIN1
data line.
Table 2
outlines the serial port channel allocations.
The DAI digital audio serial ports support 6 formats with varying bit depths from 16 to 24 as shown in
Fig-
ure 17
,
Figure 18
,
Figure 19
,
Figure 20
,
Figure 21
and
Figure 22
. These formats are selected using the
configuration bits in the
“Misc. Configuration (address 04h)” on page 52
.
Serial Data Inputs
Data mode
Channel Assignments
DAI_SDIN1
Normal (I²S,LJ,RJ)
One Line #1 or #2
TDM
PWMOUTA1(left channel)/PWMOUTB1(right channel)
PWMOUTA1/A2/A3/B1/B2/B3
PWMOUTA1/A2/A3/A4/B1/B2/B3/B4
DAI_SDIN2
Normal (I²S,LJ,RJ)
One Line #1 or #2
TDM
PWMOUTA2(left channel)/PWMOUTB2(right channel)
not used
not used
DAI_SDIN3
Normal (I²S,LJ,RJ)
One Line #1 or #2
TDM
PWMOUTA3(left channel)/PWMOUTB3(right channel)
not used
not used
DAI_SDIN4
Normal (I²S,LJ,RJ)
One Line #1 or #2
TDM
PWMOUTA4(left channel)/PWMOUTB4(right channel)
PWMOUTA4/B4
not used
Table 2. DAI Serial Audio Port Channel Allocations