HAL_SPI_Transmit_DMA. If I transmit a big amount of data (30000 bytes), it fail

[JosepM Ribera]

Hi!

I'm using STM32H7 for a new project, and I need to send data through HAL_SPI_Transmit_DMA to an external MRAM.

I have a block of 34000 bytes. If i send this: HAL_SPI_Transmit_DMA(&MRAM_SPI_H, buf, 34000); there is some write problem (when I read the data, some bit is changed so the CRC error takes place).

However, If i send the same block of data but divided in few parts (for example, parts of 5000 bytes): HAL_SPI_Transmit_DMA(&MRAM_SPI_H, buf, 5000) then the data reading is completely correct.

The maximum size of the SPI transaction is uint16_t so, what could be the problem?

Thank you so much in advance

Josep

[Tesla DeLorean]

>>what could be the problem?

Cache coherency? MPU memory region setting?

Does the memory device have a transactional limit or timeout?

[JosepM Ribera · Accepted solution]

Solved.

The problem was the timeout value of the reading function. The reading is using regular SPI HAL_SPI_Receive and the timeout value wasn't enough for the 34KB.

Thank you