Kinetis MicrocontrollersのトピックRe: eDMA channel idle

eDMA channel idle

martindusek — Thu, 24 May 2018 11:59:12 GMT

Hi,

how to check whether a dma channel is free to execute new DMA request? I thought about using ACTIVE and DONE bits of CSR register, but it seems they are not suitable for that.

Checking DONE == 1 works only when there was previous DMA transaction (it doesn't work if the DMA channel hasn't been used yet).

And ACTIVE is set to 0 on minor loop completition. I want something that tells me all major loops (whole tranaction) has been completed.

Thanks for help.

Re: eDMA channel idle

mjbcswitzerland — Thu, 24 May 2018 15:08:15 GMT

You could do a single dummy transfer during system initialisation in order to prepare the DONE bit and then use it as flag during subsequent operations.

Regards

Mark

Re: eDMA channel idle

martindusek — Thu, 24 May 2018 15:34:51 GMT

Hi Mark,

thanks. I'll do it If this is the only possibility...