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SDIO/SDMMC DMA request mapping

Question asked by Peter Flox on Nov 9, 2015
Latest reply on Nov 10, 2015 by gonzalez.laurent

I have recently got my SD card running on an STM32F7 with the SDMMC (with DMA) and came across one issue. The DMA request mapping in the Reference Manual (Table 25. DMA2 request mapping) indicates two streams for this peripheral, stream 3 and stream 6. As neither of them is tagged with RX or TX, I thought I only need one (SDMMC is only receiving OR transmitting anyway).
After some fiddling it turns out that stream 3 works only for RX and stream 6 only for TX. That messes up my project a bit because I only planned to sacrifice one stream for it (stream 6 is already used by SPI6 in my case).

Can anybody confirm this is indeed true? Or did I miss something and I actually can use only one stream for RX and TX alternating?

Best regards,

PS: STM32F4 manual has the same issue.