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Question asked by Sam Ho on May 9, 2018
Latest reply on May 10, 2018 by Clive One

I am currently using stm32h743ZI nucleo board with a Sparkfun SD/MMC card breakout and SanDisk class 10 8 GB SDHC micro sd card (with adapter).


I have a similar working project for F767zi nucleo, am now trying to port it over to H743zi nucleo.  


I am facing the problem where if I use 4bit SDIO then I get error callbacks. DCRCFAIL flag is set.  However If i just use 1 bit SDIO then everything works fine. (f_mount, f_open read write etc) 


Tried a lower clock freq but that doesn't seem to work.  I havent tried removing SB116 or SB117 as this was not needed for F7.  For my 1 bit SDIO to work on H7 nucleo I had to pull up of SDIOs otherwise, I wont see any CMDs. just spikes.  


Why would it work with 1 bit SDIO but not 4 bit SDIO?  likely to be a hardware problem?  Help/advice needed. Thanks everyone!