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/
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Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
LSB alignment standard
In 16-bit or 32-bit full-precision frame format, LSB alignment standard is the same as MSB alignment standard.
Figure 21-20 LSB alignment 16-bit or 32-bit full precision, CLKPOL = 0
Figure 21-21 LSB aligns 24-bit data, CLKPOL = 0
If the 24-bit data needs to be packed into the 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 0xXX95 (only the lower 8-bit data is valid, the upper 8-bit data is meaningless and can be any value)
into the SPI_DAT register, and then write 0xAA66 into the SPI_DAT register. If the user receives 24-bit data
0x95AA66, the CPU will first read the SPI_DAT register to get 0x0095 (only the lower 8 bits are valid, the upper 8
bits are always 0), and then read the SPI_DAT register to get 0xAA66.
CLK
WS
SD
Left channel (16-bit or 32-bit)
Right channel
Send
Receive
LSB
MSB
MSB
CLK
WS
Send
Receive
SD
Left channel 32-bit
Right channel
MSB
LSB
24-bit data
8-bit data
forced 0
MSB