SD-Card mount with FATFS and SDMMC is stuck at following HAL-Routine. STM32H750ZB, custom Board.

NZieg.1 · ‎2021-02-17

I hope someone can help me,

I'm trying to mount my SD-Card and following that writing data on it. While trying to mount the SD-Card to the Microcontroller the mounting process gets stuck in the while-loop mentioned in the picture attached to the post. Before developing the custom board I tried the SD-Card (FATFS and SDMMC) with an STMF746-Discovery board. Everything worked there as intended. My code is generated by the STM32CubeIDE V1.5.1. The FATFS-Version is R0.12c. I use a 4 Bit wide BUS with 4096 MAX_SS and LFN enabled. The SDMMC is running at a clock of 48MHz. I used different prescalers in order to find the mistake because I think is clockrelated. In the working STM32F746-Dicovery Programm I used 48MHz with a prescaler of 32. No success with this setting on the custom board and the STM32H750ZB.

I hope someone is able to help me with my problem or has some more suggestions what I can try. I now trying to fix this issue for 2 days straight.

Kind Regards

N. Ziegler

PMath.4 · ‎2021-02-17

This is almost always a H/W problem. make sure pullup resistors on the data lines are not lower than 47K and that there is no pullup on the CLOCK line. CMD seems OK with or without 47K

NZieg.1 · ‎2021-02-18

thanks for the hints. I'll try out the things you mentioned because we use 10k Pullups as well as the Clock-Line uses a pullup. If I get any more news I will post it here.

NZieg.1 · ‎2021-02-26

We corrected the possible mistakes you metioned but the sd card initialisation still gets stuck at the same HAL-routine. Is there anything else what needs to be looked at when you use a SDMMC which is directly connected to the SD-Card-Adapter. I see examples in the internet where an ESD-Filter is in use. Is this a possible issue?.

PMath.4 · ‎2021-02-26

I would try with MAX_SS and MIN_SS both set to 512. I've never tried anything other than 512 and you need to remove all "deviations" from normal until you get things working

Jjs.1 · ‎2021-03-02

Hi,Has the problem been solved? I'm trying to use the STM32L4R9ZI to mount my SD-Card,but the program gets stuck at the same place where you have problems.