I had to do the following changes for slave mode (using external clock) on ESP32:
It seems to capture sd interface signals stable with 20 MHz clock.

Thanks a lot! Static 40 MHz sample rate seems to work fine for my use case. I would also like to send packages at 40 MHz as a kind of automation. I will try to figure out how.

Thank you so much. I am using ESP32 (pico) in my project. Will the same work with that as well?

It sounds good. And can I use the CLK pin of the external sdmmc host as clock source instead of the internal clock?

Hi, I would like to use your logic analyzer for capturing CMD pin traffic of sdmmc interface. Is it possible to use CLK pin of sdmmc as clock source? sdmmc runs at 40 MHz in my case.