DMA-controller doesn't generate an interrupt after changing the transaction type once

Good morning Frederik,

I can not confirm it for sure. But actually I think it is the same problem or bug.

We are using the DMA in combination with UART. Even if we don't change the transfer type (in our case it is always BYTE), we sometimes aborted the direction of the transfer. Meaning that we clear the GO-bit before transfer is done, changing from RCON to WCON (or vice-versa) and setting up a new transfer, which ends with setting the GO-Bit again.

But this didn't work out. No interrupt was asserted, so we had to reset the DMA by writing the SOFTWARERESET-bit twice. Then it worked, even for aborted transfers.

Unfortunately it is some time ago we recognized this problem. So I don't know exactly if the the length register was zero. But I know for sure that the BUSY-bit was still set, but nothing happened. Resulting in no interrupt.

And I am pretty sure we set up the DMA right, after aborting the previous transfer.

I assume it's a similar problem/bug. But that's only my assumption....

Regards from NRW,

Philipp

P.S. : Yeah, I am german. Don't get my nickname wrong. Got something to do with sports.....