4-bit MCI SD card interface, any docs or example code?

Development Boards MicroMod
1

Has anybody implemented the 4-bit MCI SD card interface on LPC23xx or LPC24xx? Or on any processor.

Is there any example code out there?

There’s quite a bit of info in the LPC23 manuals but not really enough to put together a practical system. A while ago Sandisk had a pretty good .pdf about this, which now seems to be censored right where the good stuff starts. Should have saved it then.

Would appreciate your input, thanks!

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klopter:
A while ago Sandisk had a pretty good .pdf about this, which now seems to be censored right where the good stuff starts.

Try the MMC standard. The latest version is freely available at the mmca.org website.

3

denial:
Try the MMC standard. The latest version is freely available at the mmca.org website.

Thanks, that looks to pretty thorough. Frankly though, I just gave up and will go with the old SPI interface this time around, which I have found still works OK with at least the SanDisk Micro_SD 2GB. However it's a little scary to think that SPI is "optional" in the Micro_SD spec itself, and I presume also in the new high capacity cards. Sooner or later we're going to have to crack the 4-bit interface.