SD Card question?

Feb 25, 2005 1 Replies
C

Hello to anyone!



I'm designing SD host controller core and I have some question to someone who known about it. I've made SD controller with 1 bit data line and I want to make 4 bit data line interface with SD, but all the same after sending to SD Card ACMD6, data received by 1 wire.



I'm doing next:



(wait for 90 clock) -> CMD0 -> CMD55 -> ACMD41 (with repeate) -> CMD2



-> CMD3 -> -> CMD7 (with RCA) -> ACMD6 (4 bit) -> CMD17



One date line mode does work but 4 data line doesn't work.



Any ideas?



Thanks!


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R

What doesn't work?

Do you get any data at all?

One problem I had was with CRCs for 4 bit mode.

CRC's are computed on individual data lines, I made the mistake of using the final 8 bytes of data as the CRC's, but the bits are more like individual serial lines with individual 16 bit CRCS at the end of the data.

Rufus

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