Serial Audio Interface/Inter-IC Sound

The SAI interface (Serial Audio Interface) offers a wide set of audio protocols due to its flexibility and wide range of configurations. Many stereo or mono audio applications may be targeted. I2S standards, LSB or MSB-justified, PCM protocols may be addressed for example. SPDIF output is offered when the audio block is configured as a transmitter. To bring this level of flexibility and reconfigurability, the SAI contains two independent audio subblocks. Each block has it own clock generator and I/O line controller. The SAI works in master or slave configuration. The audio subblocks are either receiver or transmitter and work synchronously or not (with respect to the other one). The SAI can be connected with other SAIs to work synchronously.

• Independent two SAI(SAI1,SAI2)
• Independent audio subblocks which can be transmitters or receivers with their respective FIFO in SAI
• 16-word integrated FIFOs for each audio subblock
• Synchronous or asynchronous mode between the audio subblocks
• Possible synchronization between multiple SAIs
• Master or slave configuration independent for both audio subblocks
• Clock generator for each audio block to target independent audio frequency sampling when both audio subblocks are configured in master mode
• Data size configurable: 8-, 10-, 16-, 20-, 24-, 32-bit
• Audio protocol: I2S(I2S_Philips_standard, I2S_LSB or I2S_MSB-justified,long-PCM or short-PCM), TDM, AC’97, spdif, PDM
• PDM interface, supporting up to 4 microphone pairs , and master rx mode
• Free protocol(I2S, LSB or MSB-jestified,short pcm,long pcm) interface, supporting up to 4 wires
• SPDIF output available if required
• Up to 16 slots available with configurable size
• Number of bits by frame can 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
  • 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
• Interruption sources when enabled:
  • Errors,
  • FIFO requests
• 2-channel DMA interface in SAI