Hardware connection for uSD 4 Wire Bus

[Damange92]

Hello,

There is any schematic example for the connection between uSD and the STM32H7?

I'm currently using a OLIMEX E407 with a STM32H7 instead of a STM32F4. It seems that I have problems with the signals integrity. I can read and write with a 1MHz clock, if i go up with the frequency i can't write but i can read, like the problem is in the uSD side. If I increase the clock near the maximum possible, I can't even read.

Thanks in advantage,

Luca

[Tesla DeLorean]

Use similar length traces without stubs.

Use 33-47K pull ups on D0,D1,D2,D3, CMD, CARDDET at the SOCKET

Dial back the slew-rate, you don't need to push a 200 MHz edges down 2" of trace. ie SLOW or MEDIUM

Consider 33R series resistors if you're seeing ringing.

Turn OFF the use of the SD TRANSCEIVER in stm32h7xx_hal_conf,h

Have MicroSD cards simply attached to NUCLEO-H743ZI boards.

https://www.waveshare.com/micro-sd-storage-board.htm

https://www.waveshare.com/w/upload/8/83/Micro-SD-Storage-Board-Schematic.pdf