Problem using the HAL libraries for memory to SDRAM transfer using DMA

[dhavalhparikh26]

Posted on June 29, 2014 at 10:50

Hello All,

I�m trying to read and write data from memory to SDRAM using DMA. I�ve used the STM32 Cube software to generate the initialization code which uses the HAL libraries. I'm using the STM32F429 discovery board.

I was able to read and write data to SDRAM WITHOUT using DMA.

And I was also able to use DMA to transfer data between 2 arrays.

But, when I set the destination address as 0xD0000000 (since I�m using SDRAM bank 2) and after writing data to that location, when I read it, I always get 0x00.

These are the HAL functions which I have used:

1)

      1)

HAL_SDRAM_Write_32b() and HAL_SDRAM_Read_32b().

These functions write and read data to the SDRAM without DMA. They work fine.

2)

      2)

HAL_DMA_Start_IT() or HAL_DMA_Start().

These functions are used for transfer of data between source and destination address using DMA. I was able to transfer data between 2 arrays using this function. But, when I specify the SDRAM address, it doesn�t work. It just reads 0x00. So I think it doesn�t write anything to that location in the first place.

3)

      3)

HAL_SDRAM_Write_DMA() and HAL_SDRAM_Read_DMA().

These functions are used for writing and reading of data to SDRAM using DMA. Internally, they call the HAL_DMA_Start_IT(). I used these functions, but it didn�t work.

I�m attaching my main.c file which has all the initialization of the SDRAM and DMA and the function calls.

I�m also attaching the following header files and .c files.

1)

      1)

Stm32f4xx_hal_sdram.c and Stm32f4xx_hal_sdram.h

They contain the HAL_SDRAM_Write_32b(), Read_32b(), HAL_SDRAM_Write_DMA() and Read_DMA().

2)

      2)

Stm32f4xx_hal_dma.c and Stm32f4xx_hal_dma.h

These files have the HAL_DMA_Start_IT() and HAL_DMA_Start() functions.

It would be really helpful if someone could guide me and help me out.

Thank you.

#dma #sdram #discovery #hal #stm32