I am trying to write an sdio host controller. sdio is an extension to the sd/mmc protocol used on memory cards. It is used for pda peripheral devices, for example.
Note that this question is about the sdio protocol, not the spi protocol that is part of the sdio/sd/mmc specification.
I am able to send and receive a response on the cmd line, but when I send or request data, I never see it on the data lines.
Specifically, cmd52 works for both read and write and I get the correct response. But while cmd53 responds on the cmd line, I never see activity on the data lines.
Does anyone know what I am missing?
Alan Nishioka snipped-for-privacy@nishioka.com