STM32F439 SDIO DMA CMD Response Timeout

[AWied.1]

Hello guys,

I'm using a STM32F439 Board and try to use FatFS together with a SDIO (eMMC).

Additionally I try to read and write with DMA.

Now I generated a very big text file and want to write this on the eMMC. The file will be transmitted via Ethernet so it's never sure that full 512 byte blocks will be written to the eMMC.

Sometimes everything works fine but sometimes I get a CMD_RSP_TIMEOUT. Everytime I look in the FIFO register I see a value like 0x0000xxxx.

It seems that this causes the timeout but I don't know why this should cause an error.

I know this could coincidence but it would be a very big coincidence if the timeout everytime occurs when FIFO register is filled with zeros at these two bytes.

Does anyone has an idea?

Thanks in advance

[AWied.1]

Now I know that the data I get written in my FIFO buffer are just corrupt. What could be a reason for DMA writing wrong data to this buffer?

[AWied.1]

Got the problem. I tried another MMC card and everything worked fine