App note: USB audio bridge example with STM32F0 MCUs


App note from STMicroelectronics using their STM32F0 microcontrollers to playback audio stream from USB. Link here (PDF)

This application note describes a method and an example of synchronizing audio playback or audio recording with an upstream or downstream USB audio host, ensuring flawless audio listening or recording using only internal MCU resources.

Focusing on specific properties of USB microcontrollers from the STM32F0 family, the application note describes how the CRS unit can be beneficially employed for USB audio streaming synchronization. In particular, it elaborates a method of HSI48 clock frequency trimming to compensate for timing differences due to independent USB host (computer) and device (STM32F0) clock domains.