shutdown.h

void ma_shutdown(const chanend_t c_frame_in)

Shut down the mic array thread(s).

This function is called by the application to terminate the mic array threads. It causes the decimator (and PDM rx if running in thread context) thread(s) to exit. This is required if the mic array needs to be restarted with a different configuration (a different output sampling rate for instance). After shutdown, the mic array can be initialised and started with a different configuration.

Note

This function returns only after the mic array thread(s) have exited.

Warning

Ensure that ma_frame_rx() or ma_frame_rx_transpose() is not being called concurrently when calling ma_shutdown().

Warning

The mic array threads check for shutdown only at PDM frame boundaries. If PDM data is not being received (for example, if MCLK is stopped), the threads will stall and fail to detect the shutdown request. Ensure that MCLK remains active during shutdown so that PDM frames continue to arrive.

Parameters:

• c_frame_in – chanend used to receive audio frames from the mic array. This must be the same chanend passed to ma_frame_rx() or ma_frame_rx_transpose() when the application receives a frame from the mic array. Shutdown is signalled to the mic array over the same chanend.