SDIO CMD53 Help

[Guest]

Hello!

I am trying to interface to an SDIO device using SPI. Everything is working pretty well, but CMD53 sometimes acts a little funky (at low clock rates I have a workaround, but at high clock rates it is doesn't work correctly at all). If I refer to the Simplified SDIO spec it tells me that there is special timing requirements for CMD53, and that it is documented in the full SDIO spec. I don't have the full SDIO spec. :(

Can anyone with SDIO experience or the full SDIO specification give some helpful insights? Or refer me to the proper discussion forum?

Thanks!