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AT32F413
Series Reference Manual
2022.06.27
Page 170
Rev 2.00
Figure 13-16
I
2
S master device transmission
I2S master
CK
SD
WS
I2S slave
CK
SD
WS
Master device reception:
Set the I2SMSEL bit, and OPERSEL[1: 0]=11, the I
2
S will work in master device repection mode.
Figure 13-17
I
2
S master device reception
I2S master
CK
SD
WS
I2S slave
CK
SD
WS
13.3.3 Audio protocol selector
While used as I
2
S, the SPI supports multiple audio protocols. The user can control the audio protol
selector through software configuration to select the desired audio protocol, with the number of data bits
and channel bits controlled by the audio protocol selector. Besides, the user can also select the number
of data bits and channel bits by software. Meanwhile, the audio protocol selector manages the WS
controller, output or detect the WS siganal that meets the protocol requirements.
Select audio protocol by seeting the STDSEL bit
STDSLE=00: Philips standard
STDSLE=01: MSB-aligned standard (left-aligned)
STDSLE=10: LSB-aligned standard (right-aligned)
STDSLE=11: PCM standard
Select PCM frame synchronization format: PCMFSSEL=1 for PCM long frame synchronization,
PCMFSSEL=0 for short frame synchronization (this step is required when selecting PCM
protocol)
Select data bits by setting the I2SDBN bit
I2SDBN=00: 16 bit
I2SDBN =01: 24 bit
I2SDBN =10: 32 bit
Select channel bits by setting the I2SCBN bit
I2SDBN =0: 16 bit
I2SDBN =1: 32 bit