Figure 364. I 2 S Philips Protocol Waveforms (16/32-Bit Full Accuracy); Figure 365. I 2 S Philips Standard Waveforms (24-Bit Frame) - ST STM32WL55JC Reference Manual

Serial peripheral interface / integrated interchip sound (SPI/I2S)
CK
WS
SD
LSB justified standard
This standard is similar to the MSB justified standard (no difference for the 16-bit and 32-bit
full-accuracy frame formats).
The sampling of the input and output signals is the same as for the I
CK
WS
SD
•
In transmission mode:
If data 0x3478AE have to be transmitted, two write operations to the SPIx_DR register
are required by software or by DMA. The operations are shown below.
1290/1454
Figure 371. MSB justified 16-bit extended to 32-bit packet frame
Transmission
16-bit data
MSB
Channel left 32-bit
Figure 372. LSB justified 16-bit or 32-bit full-accuracy
CK
WS
Transmission
16- or 32-bit data
SD
MSB
Channel left
Figure 373. LSB justified 24-bit frame length
8-bit data
0 forced
Reception
16-bit remaining
0 forced
LSB
Reception
LSB
MSB
Channel right
Transmission
24-bit remaining
MSB
Channel left 32-bit
RM0453 Rev 2
Channel right
2
S Philips standard.
Reception
LSB
Channel right
RM0453
MS30102V1
MS30103V1
MS30104V1