第七章 STM32L4串行音频接口模块(SAI)介绍.pdf

Serial Audio Interface ( SAI ) 02/07/2015 STM32L476 Technical Training SAI Introduction The SAI interface (Serial Audio Interface) is a peripheral supporting a wide set of audio protocols thanks to its flexible architecture: • I2S Philips standards, (Inter-IC Sound), • I2S LSB or MSB-justified, (Variant of Inter-IC Sound), • SPDIF Output, (Sony/Philips Digital InterFace) • PCM, (Pulse Code Modulation) • TDM, (Time Division Multiplexing) • AC’97, (Audio Codec ’97 from Intel) 02/07/2015 STM32L476 Technical Training 43 SAI Features(1/2) • A SAI embeds two independent audio sub-blocks which can be: • Transmitter and/or receiver • Master or slave • Synchronous or asynchronous mode between the audio sub-blocks • Clock generator for each audio sub-block to target independent audio frequency sampling • 8-word integrated FIFOs for each audio sub-block. • Up to 16 slots available • Mute mode • Stereo/Mono audio frame capability. • Companding mode supporting µ-Law and A-Law. 02/07/2015 STM32L476 Technical Training 44 SAI Features(2/2) • Flexible serial interface: – Configurable data justification (LSB or MSB first), – Configurable data and slot size, – Configurable sampling edge for the Communication clock, – Configurable number of bits per frame, – Configurable data position within a slot, – Configurable frame synchronization active level, – Configurable frame shape • 2 DMA interfaces : one for each audio sub-block • 2 Interrupt lines: one for each audio sub-block 02/07/2015 STM32L476 Technical Training 45 SAI Block Diagram STM32L476/486