Issue in enabling the DMA channel.

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by suhel on Sun Jun 01 22:52:30 MST 2014

We are working on LPC_4370 device and we want to use HSADC in DMA mode. The issue we face is as below,

"when we try to enable the DMA channel, by setting the Channel enable bit as part of the DMA channel[0] configuration register, it just won't get set and is always zero."

The above behavior is seen with DMA controller Enable (CONFIG register) already set. but on trying to enable the channel first we could see that the channel enable bit gets set, only to get cleared when the DMA controller Enable is set.

what could be the possible cause, are we allowed to use DMA channle 0 for ADCHS read or not?

Over all idea of our requirement is as below,

We want to use HSADC operating with @ sample frequency of 40 M samples/s, with DMA.

We are using HSADC channel 0, and DMA channel 0 for the same.

steps we followed in code,

1. Configure DMA channel
2. Enable DMA channel
3. Enable HSADC
4. Create a Software trigger.

Please let us know, where we are going wrong, I have included our routines as attachment.


Original Attachment has been moved to: code.zip