How to prevent edma TCDn_CITER from auto reloading TCDn_BITER

[huangjia]

Hi dears, i want to send uart data by edma on s32k344. I called Uart_asyncSend() funciton in uart.c to send data, but it can only send one time in dma mode. I debuged the function code in single step mode, found TCDn_CITER had reloaded the value from TCDn_BITER after the first tranfer finish, then it returned a busy error.

So how to set the register to prevent TCDn_CITER from auto reloading TCDn_BITER?

Thanks.

[davidtosenovjan · Accepted solution]

Could you show error status register?

Use DREQ bit if you don't want another transfer after end of major loop. Or check DLAST field in the TCD whether it does not point to some invalid address, if you want to trigger another major loop.