Main Features; Functional Block Diagram - ST STM32F423 Reference Manual

Serial audio interface (SAI)
30.2

Main features

• Two independent audio sub-blocks which can be transmitters or receivers with their
respective FIFO.
•
8-word integrated FIFOs for each audio sub-block.
•
Synchronous or asynchronous mode between the audio sub-blocks.
•
Master or slave configuration independent for both audio sub-blocks.
•
Clock generator for each audio block to target independent audio frequency sampling
when both audio sub-blocks are configured in master mode.
•
Data size configurable: 8-, 10-, 16-, 20-, 24-, 32-bit.
•
Peripheral with large configurability and flexibility allowing to target as example the
following audio protocol: I2S, LSB or MSB-justified, PCM/DSP, TDM, AC'97
• Up to 16 slots available with configurable size and with the possibility to select which
ones are active in the audio frame.
•
Number of bits by frame may be configurable.
•
Frame synchronization active level configurable (offset, bit length, level).
•
First active bit position in the slot is configurable.
•
LSB first or MSB first for data transfer.
•
Mute mode.
•
Stereo/Mono audio frame capability.
•
Communication clock strobing edge configurable (SCK).
•
Error flags with associated interrupts if enabled respectively.
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–
–
–
•
Interruption sources when enabled:
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• DMA interface with 2 dedicated channels to handle access to the dedicated integrated
FIFO of each SAI audio sub-block.
30.3

Functional block diagram

The block diagram of the SAI is shown in
988/1324
Overrun and underrun detection,
Anticipated frame synchronization signal detection in slave mode,
Late frame synchronization signal detection in slave mode,
Codec not ready for the AC'97 mode in reception.
Errors,
FIFO requests.
Figure 351.
RM0430 Rev 8
RM0430