GD32W51x User Manual
690
Figure 20-33. LSB justified standard timing diagram (DTLEN=00, CHLEN=1, CKPL=1)
I2S_CK
I2S_SD
16-bit 0
frame 1 (channel left)
frame 2 (channel right)
I2S_WS
16-bit data
MSB
LSB
When the packet type is 16-bit data packed in 32-bit frame, only one write or read operation
to or from the SPI_DATA register is needed to complete
the transmission of a frame. The
remaining 16 bits are forced by hardware to 0x0000 to extend the data to 32-bit format.
PCM standard
For PCM standard, I2S_WS and I2S_SD are updated on the rising edge of I2S_CK, and the
I2S_WS signal indicates frame synchronization information. Both the short frame
synchronization mode and the long frame synchronization mode are available and
configurable using the PCMSMOD bit in the SPI_I2SCTL register. The SPI_DATA register is
handled in the exactly same way as that for I2S Phillips standard. The timing diagrams for
each configuration of the short frame synchronization mode are shown below.
Figure 20-34. PCM standard short frame synchronization mode timing diagram
(DTLEN=00, CHLEN=0, CKPL=0)
I2S_CK
I2S_SD
16-bit data
MSB
I2S_WS
MSB
LSB
frame 1
frame 2
Figure 20-35. PCM standard short frame synchronization mode timing diagram
(DTLEN=00, CHLEN=0, CKPL=1)
I2S_CK
I2S_SD
16-bit data
MSB
I2S_WS
MSB
LSB
frame 1
frame 2
Figure 20-36. PCM standard short frame synchronization mode timing diagram
(DTLEN=10, CHLEN=1, CKPL=0)
I2S_CK
I2S_SD
32-bit data
MSB
I2S_WS
MSB
LSB
frame 1
frame 2
Figure 20-37. PCM standard short frame synchronization mode timing diagram