Posted on October 04, 2011 at 05:35Yoou're going to have to be a lot more specific than just saying you're ''experiencing a problem'' if you're wanting any specific help.
I'd assume you're accessing the card in 4-bit parallel mode, and not SPI mode, seeing as you say you're using the ST libraries.
Do you have a level converter between the card and your processor? If so, try running at a slower SDIO clock speed and see if that helps.
The ST library code is riddled with problems, as discussed in this thread. The timeouts can, and do, timeout prematurely, generating errors when none should exist. You need to replace them with a timeout system of your own making (normally you'd have a timebase of some type already in the system, if not, take a look at the timer examples in the ST library).
For a 2 GB SD card, as was stated earlier, you may need to issue a blocksize command (CMD16) to the card, to tell it your blocksize is 512 bytes. I haven't personally seen this problem, but obviously other people have.
The library code doesn't pick up on a lot of errors. For example, the card can sometimes not be ready to accept data but the library code can try to write to it anyway, because it doesn't realise, resulting in write errors and timeouts.
Card initialisation can be a challenge - this was discussed in another thread on this board somewhere (but good luck using the search function to find it). The essence of it was, before doing the card initialisations, set the SDIO GPIO pins to be outputs and set them high, to present an idle state to the card, for a few milliseconds. Then do the SDIO initialisations (including changing the pins to their alternate function, in this case SDIO). This helped me a lot.
At the end of the day, you need to take the attitude that the ST SDIO library code is only example code, to give you a flavour of how to do it. For real-world, reliable, production code you're going to need to write it yourself.
