DMA is not working with SAI

[rubenles]

hi,

I am using stm32h743zit6.

I am having problems with DMA in my code. First i have a code that is not mine that takes data from a peripheral (a microphone) using SAI and then via DMA inserts this data into an array (a buffer). To do this memory is modified to do this.

I am doing the same configuration in other code to try to do this, in the original one the data refreshes automatically and in my own code, it just takes the first read.

ALIGN_32BYTES (int32_t __attribute__((section (".dmapart"))) dmaArray[data]);
HAL_SAI_Receive_DMA(&hsai_BlockA3,(uint8_t)* dmaArray, (uint16_t) data);

All the GPIO is ok because i just copied the same code. SCB_EnableIcache() is written in the main..., I don't know why is not  updating the data in my array and is working well in the other code. Anyone have any idea why is not updating in my code?

If any of you need more info about the code tell me please. 

Thank you so much, i am desperating.

[AScha.3]

Hi,

DMA -> in circular mode , for continuous data transfer. Did you set it to circular ?

[rubenles]

Yes, it is configured as circular. @AScha.3 

[KDJEM.1]

Hello @rubenles ,

Maybe the issue is related to two things: memory layout on STM32H7 and internal data cache (D-Cache) of the Cortex-M7 core.

Fore that, I recommend you to take a look to this FAQ: DMA is not working on STM32H7 devices .

Thank you.

Kaouthar

[rubenles]

Hello @KDJEM.1 ,

I tried to modify these memories, first in the .Id file:

/* DMA Array data section */
  . = ALIGN(4);
  .dmaArray :
 {
 	_sdmaArray = .;
 	__dmaArray_start__ = _sdmaArray;
 	*(DMA)
 	. = ALIGN(4);
    KEEP(*(.dmaArray)) 	
    
    _edmaArray = .;
    __dmaArray_end__ = _edmaArray;
  } >RAM_D2 AT> FLASH

MEMORY
{
  DTCMRAM	(xrw)	: ORIGIN = 0x20000000,	LENGTH = 128K
  ITCMRAM	(xrw)	: ORIGIN = 0x00000000,	LENGTH = 64K
  RAM_D1_P	(xrw)	: ORIGIN = 0x24000000,	LENGTH = 4K
  RAM_D1    (xrw)	: ORIGIN = 0x24001000,	LENGTH = 508K
  RAM_D2	(xrw)	: ORIGIN = 0x30000000,	LENGTH = 288K
  RAM_D3	(xrw)	: ORIGIN = 0x38000000,	LENGTH = 64K
  FLASH	    (rx)	: ORIGIN = 0x08000000,	LENGTH = 1920K
  FLASH_P   (xrw)	: ORIGIN = 0x081E0000,	LENGTH = 128K
  RAM_BCK	(w)		: ORIGIN = 0x38800000,  LENGTH = 4K
}

  ._user_heap_stack :
  {
    . = ALIGN(8);
    PROVIDE ( end = . );
    PROVIDE ( _end = . );
    . = . + _Min_Heap_Size;
    . = . + _Min_Stack_Size;
    . = ALIGN(8);
  } >RAM_D1 AT> FLASH

After this, my array just save the first value and then stops, i need it refreshing all the time. I don't know where can i have the problem...

Thank you so much for your time and help!

[KDJEM.1]

Hi @rubenles ,

Could you please check the initial stack definition?

In some linkerscripts, the initial stack is defined separately. So you either need to update it with the section, or define it inside the section like:

._user_heap_stack : 
{ 
 . = ALIGN(8); 
 PROVIDE ( end = . ); 
 PROVIDE ( _end = . );
 . = . + _Min_Heap_Size;
 . = . + _Min_Stack_Size; 
 _estack = .; /* <<<< line added */
 . = ALIGN(8); 
} >RAM_D1

and remove the original _estack definition.

Please let me know if the issue is solved or not.

Thank you.

Kaouthar

[rubenles]

I tried it and still not working :frowning_face: Any possible modification y project settings or something like this?

Thank you so much @KDJEM.1 

[KDJEM.1]

Hi @rubenles ,

Thank you for updating post.

I advise you to take a look at the SAI examples in STM32CubeH7 and refer to them to check the SAI and the DMA configuration settings.

• \STM32Cube_FW_H7_V1.11.1\Projects\STM32H743I-EVAL\Examples\SAI\SAI_AudioPlay
• \STM32Cube_FW_H7_V1.11.1\Projects\STM32H743I-EVAL\Examples\SAI\SAI_AudioPlayback

I hope this help you!

Thank you.

Kaouthar

[rubenles]

Sorry for asking it but, where can i find these examples?? I am looking for it and i didn't find anything

Thanks. @KDJEM.1 

[KDJEM.1]

Hi @rubenles ,

You can download the latest version of STM32CubeH7 package from this link: STM32CubeH7 - STM32Cube MCU Package for STM32H7 series (HAL, Low-Layer APIs and CMSIS, USB, TCP/IP, File system, RTOS, Graphic - and examples running on ST boards) - STMicroelectronics

Then you can find these examples under these paths:

• ....\STM32Cube_FW_H7_V1.11.1\Projects\STM32H743I-EVAL\Examples\SAI\SAI_AudioPlay
• ....\STM32Cube_FW_H7_V1.11.1\Projects\STM32H743I-EVAL\Examples\SAI\SAI_AudioPlayback

Also, the SAI_AudioPlay example is available in this link STM32CubeH7/Projects/STM32H743I-EVAL/Examples/SAI at master · STMicroelectronics/STM32CubeH7 · GitHub

Thank you.

Kaouthar