SDIO FATFS SDMMC_ERROR_COM_CRC_FAILED

[vbesson]

Hello, 

I am using a STM32F411 with SDIO (4bit) and fatfs

When reading block I have regular SDMMC_ERROR_COM_CRC_FAILED error, from 

SDMMC_GetCmdResp1 function. 

What could be the reason for such error ? thanks

Vincent 

[Tesla DeLorean · Accepted solution]

Data corruption on the wire?

Signal integrity, cross talk..

Data and command line should have pullup resistors, line lengths relatively consistent. 

[vbesson]

I fixed the issue by changing the ClockDiv from 0 to 2 

Vincent