SAI Callback Types

Typedefs
typedef void(*	SAI_BufferDoneFn_t) (void *buffer, int doneInvalid)
	Callback function type for buffer completion notifications.

Detailed Description

Typedef Documentation

SAI_BufferDoneFn_t

typedef void(* SAI_BufferDoneFn_t) (void *buffer, int doneInvalid)

#include <sai.h>

Callback function type for buffer completion notifications.

This callback is invoked from interrupt context when a buffer transfer completes or encounters an error. The callback should return quickly and defer any lengthy processing to a task context.

Parameters

buffer	Pointer to the buffer that completed (same pointer passed to TransmitBuffer or ReadyReceiveBuffer)
doneInvalid	Status indicator for the buffer completion: **< -1**: Channel error, buffer state unchanged (may be retried) -1: Transfer error, buffer retired (do not reuse immediately) 0: Half transfer complete (if half-notify enabled), second half still in progress **> 0**: Buffer completely transferred successfully

Note

This callback executes in interrupt context. Keep processing minimal:

• Do NOT call blocking functions
• Do NOT perform long computations
• Use RTOS signaling (semaphores, flags) to defer work to tasks
• Avoid excessive printing

Warning

The buffer pointer is only valid if the completion status is non-negative. For error conditions (< 0), the buffer may be in an indeterminate state.

void myBufferCallback(void *buffer, int doneInvalid) {
    if (doneInvalid > 0) {
        // Success - buffer fully transferred
        OSSemPost(&bufferDoneSemaphore);
    } else if (doneInvalid == 0) {
        // Half complete - can start processing first half
        ProcessFirstHalf(buffer);
    } else {
        // Error condition
        iprintf("Buffer error: %d\n", doneInvalid);
    }
}