SD Card as MSC Device on STM32H753I-EVAL2

[ikogman]

Hello everyone,

I’m looking for some assistance with making an SD card work as a Mass Storage Class device on the STM32H753I-EVAL2 board. I’ve come across various solutions on the forum that have helped others, but none have resolved all the issues, and I’m still facing some challenges.

I have 2 specific questions:

1. The MSC_standalone example doesn’t seem to function correctly on the EVB. It recognizes the SD card and initiates communication, but it reaches a fault error. I’ve tried several SD cards with different speeds and capacities.

2. In our CUSTOM BOARD design for our product, we’ve only had succes (open the flash drive) with low-volume SD cards. I suspect this might be related to clock rates.
   
   One notable difference between the evaluation board and our custom board is the absence of a transceiver for the SD card. 

Any insights or suggestions would be greatly appreciated!

Thank you!

Itzik

[Tesla DeLorean]

STM32Cube_FW_H7_V1.11.2\Projects\STM32H743I-EVAL\Applications\USB_Device\MSC_Standalone\readme.txt

Set to ZERO #define USE_SD_TRANSCEIVER 1U

STM32Cube_FW_H7_V1.11.2\Projects\STM32H743I-EVAL\Applications\USB_Device\MSC_Standalone\Inc\stm32h7xx_hal_conf.h

Should be able to support SDHC / SDXC (most ultra) without transceiver

[ikogman]

@Tesla DeLorean Thanks for your help! 
you were 100% right about this:

Should be able to support SDHC / SDXC (most ultra) without transceiver

I managed to get it working with this configuration (on 4 out of 5 different SD cards I have, which is fine for now):

static void MX_SDMMC1_SD_Init(void)

{

hsd1.Instance = SDMMC1;

hsd1.Init.ClockEdge = SDMMC_CLOCK_EDGE_RISING;

hsd1.Init.ClockPowerSave = SDMMC_CLOCK_POWER_SAVE_DISABLE;

hsd1.Init.BusWide = SDMMC_BUS_WIDE_4B;

hsd1.Init.HardwareFlowControl = SDMMC_HARDWARE_FLOW_CONTROL_EBABLE;

hsd1.Init.ClockDiv = 8;

if (HAL_SD_Init(&hsd1) != HAL_OK)

{

Error_Handler();

}

}

and clock for SDMMC1,2 mux 200MHz.

What’s really strange now is that it works only in debug mode.
It also works fine after flashing the device in release mode - just right after the flashing process,
but when I disconnect and reconnect the power supply,
the program crashes at:

if (HAL_SD_Init(&hsd1) != HAL_OK)

{

Error_Handler();

}

}

I’d really appreciate any help with getting this to work in release mode.
Thank you!
Itzik

[ikogman]

I would like to mention that on our custom board, the SD card detect is always on (high voltage). Could this be a contributing factor to the issue I mentioned above, especially during the reset, when the SD initialization doesn't complete correctly?
I also suspect it might be related to clock synchronization, timing, due that debug mode is slower, as I spent a lot of time to get it to work in debug mode as well.