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STM32F4 SDIO 4 bit mode with CubeMX project does not work

Question asked by Andreas S. on Oct 16, 2017
Latest reply on Nov 2, 2017 by Andreas S.

Hi all,

I created a project in CubeMX for a STM32F429IGtx with SDIO and FatFs. Clock at 180 MHz,

The example works fine in 1 bit mode, but when I switch to 4 bit mode by adding the define "BUS_4BITS"

it does not work and f_write returns an FR_DISK_ERROR. Have switched to DMA, seems to work only with DMA,

but not reliably.

I found an example: STM32Cube_FW_F4_V1.16.0 -> STM324x9I_EVAL that works fine in 4 bit mode.

I have tried to set the pullups in the CubeMX example, but nothing works. I can not see whats really the difference

exept a different initialization order.

Does anyone have an idea? What are the pitfalls with SDIO in 4 bit mode?

Best regards