HRTIM burst DMA

[JRyu.1]

Hi,

I am trying to figure out to make HRTIM burst DMA working. I want to update timer period, compare1, compare2, and compare 3 registers by using burst DMA. There is not much information about this. There are two postings in the community posted several years ago, and it gave me some idea. But I need to have more information.

• I used CubeMx to configure and generate code.
• I want to trigger the burst DMA by software.
• Assuming that the DMA source buffer data order matches to the order of number of registers to update, for there is no description stated in the reference manual.
• Nothing happens when I run. It did not stop at burst DMA completion and DMA error callback function when I set breakpoints.

Below screenshots and code are used for the configuration.

 

I am not sure that I need to check on the "Increment Address" or not.

InvPerComp[0] = new_per;    // new period
InvPerComp[1] = cmp1;       // new compare 1
InvPerComp[2] = cmp2;       // new compare 2
InvPerComp[3] = cmp3;       // new compare 3
 
// Will this update the registers in order?        
HAL_HRTIM_BurstDMATransfer(hrtim, timer, (uint32_t)&InvPerComp[0], 4)

[MTall.3]

Did you find a solution to this problem? It would be interesting to know as I'm working on a similar problem.

[BKain.2]

Did you find a solution to this problem? I have a similar problem.

[Pierre_Paris]

Hello @JRyu.1 , @BKain.2 , @MTall.3 ,

Here some support and points that may help you :

• Can you confirm you use HAL_HRTIM_BurstDMAConfig() to configure HRTIM burst DMA timer x update register (HRTIM_BDTxUPR) ? Please share register values before and after executing this line.

• Which STM32 are you using ?
• Can you please share the HAL_HRTIM_MspInit() content ? Have you enable synchronization ? 

Best Regards,

Pierre

[liaifat85]

Confirm that the source buffer used for DMA holds the correct data in the correct order for updating the timer period, compare1, compare2, and compare3 registers.

[Odiug]

I am also failing in reproducing the DMA example from https://wiki.st.com/stm32mcu/wiki/Getting_started_with_HRTIM#To_go_further_about_DMA_burst.

HAL_HRTIM_BurstDMAConfig() is mentioned in the text, but not present in the code example. Did you miss to put it into the example?

Minor issue: I find it weird to edit HAL_HRTIM_MspInit() to change DMA_MEMORY_TO_PERIPH to DMA_MEMORY_TO_MEMORY as this gets overwritten by the next code generation.

Would it be safe to put this in the user section below:

    /* USER CODE BEGIN HRTIM1_MspInit 1 */
    hdma_hrtim1_a.Init.Direction = DMA_MEMORY_TO_MEMORY;

    if (HAL_DMA_Init(&hdma_hrtim1_a) != HAL_OK)
    {
      Error_Handler();
    }
    /* USER CODE END HRTIM1_MspInit 1 */

This would result calling HAL_DMA_Init() twice. Is this OK?

Kind regards,

Guido

[Odiug]

Sorry, I was wrong. HAL_HRTIM_BurstDMAConfig() is called in the autogenerated MX_HRTIM1_Init().

[Odiug]

What I would like to achieve in the end is a running HRTIM1 where the MPER register gets updated with every period. I assumed this can be achieved with burst DMA.

The example from https://wiki.st.com/stm32mcu/wiki/Getting_started_with_HRTIM#To_go_further_about_DMA_burst is the only one, I could find.

In order to learn more about burst DMA, I started experimenting. First, I wanted to update multiple registers.

I am writing to the four CMP registers and preset them with different values to visualize it better:

static uint32_t reg_update[] = {
		0xaaaa,
		0xbbbb,
		0xcccc,
		0xdddd,
};

static inline void BurstDMA_Test(void)
{
	HAL_StatusTypeDef ret;

	HRTIM1->sTimerxRegs[HRTIM_TIMERINDEX_TIMER_A].CMP1xR = 0x11;
	HRTIM1->sTimerxRegs[HRTIM_TIMERINDEX_TIMER_A].CMP2xR = 0x22;
	HRTIM1->sTimerxRegs[HRTIM_TIMERINDEX_TIMER_A].CMP3xR = 0x33;
	HRTIM1->sTimerxRegs[HRTIM_TIMERINDEX_TIMER_A].CMP4xR = 0x44;

	ret = HAL_HRTIM_BurstDMATransfer(
			&hhrtim1, HRTIM_TIMERINDEX_TIMER_A, (uint32_t)reg_update, 4);
	if (ret != HAL_OK)
	{
	   Error_Handler();
	}
}

 But that just gave me:

So, the first value is copied into all the configure registers.

OK, so maybe I have to set the "Increment Address" for the DMA configuration:

But this results in only one register being updated:

I am puzzled!

So, my first piece in understanding would be: How to update multiple registers from a single buffer.

Kind regards,

Guido