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Visitor II
December 15, 2023
Question

Usage of both SDIO interface at the same time in STM32H747

  • December 15, 2023
  • 3 replies
  • 1979 views

Hi, I observed a limitation in the STM32H7 reference manual saying that 

"The current version of the SDMMC supports only one SD/SDIO/e•MMC card at any one
time and a stack of e•MMC."

So my application requires to control two SDIO slaves from both SDIO interfaces of STM32H747 at the same time, Is this realizable?

    This topic has been closed for replies.

    3 replies

    Technical Moderator
    December 15, 2023

    Hello @Rekhas19 

    Indeed, SDMMC interface only supports one card at a time, meaning that a device can only read from or write to one card at a time.

    Rekhas19Author
    Visitor II
    December 25, 2023

    Hi Belaid,

    Thank you for replying to my query. 

     

    When i saw the HAL and LLs of STM32H7 , i could not find any reference to CMD5, CMD52 and CMD53,which are SDIO specific functions. Please excuse me, I am very new to SDIO protocol. Can you please point to any reference API or example for those commands?

    Super User
    December 25, 2023

    Hi,

    As I understand the manual, every sdmmc interface can use one card, so using both sdmmc can connect to two SD cards, one on each sdmmc interface.

    You want to use fatfs - or what? So give them two different drive names, maybe 0 and 1 .

    Technical Moderator
    December 25, 2023

    You can find SD Card Specific commands here.
    I hope this helps!