Example ADC_SingleConversion_TriggerTimer_DMA not working on NUCLEO-N657X0-Q.

[AintMina]

Hi,

Im trying to figure out how to use DMA with ADC and none of the guides or examples work...

In ADC_SingleConversion_TriggerTimer_DMA, I changed the timer prescaler and period and tried to run it, but it goes to Error_Handler() because of DMA.

Does the DMA work on this chip? I haven't been able to get it to work at all.

DMA seems to be unlocked and ready. Does the error code 4 mean something?

The init also seems to be empty.

[AintMina]

After digging a bit, I noticed that the error code 4 refers to User Setting Error or USEF bit in HPDMA_CxSR register. This flag gets raised by couple of reasons which are defined in the rm0486 datasheet page 885-886. I noticed that when I break in the DMA interrupt handler the GPDMA0 registers look like this:

and according to the first bullet point:

a programmed null source block size without a programmed update of this value
from the next LLI1 (HPDMA_CxBR1.BNDT[15:0] = 0 and
HPDMA_CxLLR.UB1 = 0)

this should not happen.

[AintMina]

When stepping into "HAL_DMAEx_List_Start_IT", right before "__HAL_DMA_ENABLE", I noticed that the UB1 bit WAS set to 1.

But BNDT register was still empty when enabling DMA and this is where the USEF bit gets raised.

– a programmed linked-list item LLIn+1 with a null data transfer
(GPDMA_CxLLR.UB1 = 1 and GPDMA_CxBR1. BNDT = 0)

I tried manually filling the CBR1 register right before enabling DMA with this:

hdma->Instance->CBR1 = ((uint32_t)hdma->LinkedListQueue->Head->LinkRegisters[NODE_CBR1_DEFAULT_OFFSET]);

And the USEF flag didn't get raised, BUT then the DMA interrupt never fired since the CBR1 register never went down to zero.

[RJMSTM]

Hello @AintMina,

I have tried to reproduce your issue, but I am unable to do so. The example is functioning correctly. As you can see in this image, the BNDT register is not empty; it is properly filled. Additionally, the value converted by the ADC is correctly received by the DMA, and the USEF flag is not set.

Could you please share with me the changes you made to the timer prescaler and period configuration?

Regards,

[AintMina]

Hi,

The changes I made to the TIM2 was Prescaler=400-1 and Counter Period=1000.
The other change I made was ADC source clock=64MHz since in the datasheet it says 70MHz is maximum.
I also tried to use IN1 and IN11 as ADC input.

BR

[AintMina]

Apparently CubeMX doesnt generate the same amount of code for CubeIDE as it does for EWARM. Could you try generating it for CubeIDE, if that would be the problem here.

[AintMina]

or actually, it doesn't generate all the code when I select "Generate peripheral initialization as a pair of '.c/.h' files per peripheral"...
I unchecked that and now it seems to work.