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

[NZieg.1]

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]

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]

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]

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]

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]

​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.