587
/
838
Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
Figure 21-14 I
2
S Philips protocol waveform (16/32-bit full precision, CLKPOL = 0)
Figure 21-15 I
2
S Philips protocol standard waveform (24-bit frame, CLKPOL = 0)
If the 24-bit data needs to be packaged into 32-bit data frame format, the CPU needs to read or write the SPI_DAT
register twice during each frame of data transmission. For example, if the user sends 24-bit data 0x95AA66, the CPU
will first write 0x95AA into the SPI_DAT register, and then write 0x66XX into the SPI_DAT register (only the upper
8-bit data is valid, the lower 8-bit data is meaningless and can be any value); if the user receives 24-bit data 0x95AA66,
the CPU will first read the SPI_DAT register to get 0x95AA, and then read the SPI_DAT register to get 0x6600 (only
the upper 8-bit data is valid, and the lower 8-bit data is always 0).
CLK
WS
SD
Left channel (data format 16-bit or 32-bit)
Right channel
Send
Receive
MSB
LSB
MSB
CLK
WS
SD
Left channel 32-bit data
Right channel
Send
Recieve
MSB
LSB
MSB
The remaining
8 bits are
forced to 0
24-bit data