SPI6 using BDMA Tx not working

[SHebb.1]

I am trying to make SPI6 work with BDMA I see that transfer completion flag set in BMA ISR but SPI registers i don't see EOT bit set. I don't see any data coming from MOSI line of SPI6. Please help me know what is going wrong. There is no error set in any of the registers I have attached a screen shot of BDMA and SPI6 registers. I am using BDMA channel 0 for Rx and BDMA channel 1 for Tx.

[waclawek.jan]

Which STM32?

> I don't see any data coming from MOSI line of SPI6.

And SCK?

Have you tried polled implementation of SPI6, or at least transmit by writing directly into registers in debugger?

JW

[SHebb.1]

Iam Using STM32H743I

[SHebb.1]

No SCK as well

[waclawek.jan]

Try polled implementation of SPI6, to make sure there's no problem in SPI itself, GPIO or clocks.

JW

[SHebb.1]

I tried in polling method after i use HAL_SPI_Transmit its waiting in 

while ((__HAL_SPI_GET_FLAG(hspi, Flag) ? SET : RESET) == Status)

for EOT flag in SR register to be set. What can be the reason for this?

I see the SPI6 registers are getting filled properly.

[GCava.2]

Hello @SHebb.1​ ,

have u define the buffer correctly?

For example, I resolved my problems in this way:

static uint8_t __attribute__ ((section (".BDMA_Access"),used)) sbuffer_tx[2];

static uint8_t __attribute__ ((section (".BDMA_Access"),used)) sbuffer_rx[2];

Then, inside the main, u can initialize the buffer, as:

sbuffer_tx[0]= 0x00;

sbuffer_tx[1]= 0x00;

and the u can use the sample HAL:

HAL_SPI_TransmitReceive_DMA(&hspi6, sbuffer_tx, sbuffer_rx,sizeof(sbuffer_rx));

Finally ".BDMA_Access" is defined inside the linker script file as:

 .BDMABlock : 

 {

  . = ALIGN(32);

  *(.BDMA_Access)

 } >RAM_D3 AT> FLASH

Bye!!!

[SHebb.1 · Accepted solution]

Hi,

Thanks for the help.

I could figure out the problem.

1. one of the problem was i was using SRAM 3 instead of SRAM 4 which is from 0x38000000 this solved the error i was getting in BDMA transfer.
2. For the EOT not getting set in SR registers of SPI6 - I had not configured port G which i was using for SPI lines as AF5. Also No pull configuration for the GPIO pins.

I am able to transfer and receive the data's using SPI6 with BDMA.