Using SPI

[The Master]

Hi, Ive done a lot of reading and it seems that the clock and be slowed down as much as you want which is good for testing. Im getting a little confused by the actual SD protocol though. Different sites are saying different things.

I have some example code in C. I dont completely understand C but it looks like its saying things should happen in this order:-
Enable the SPI interface
Send 80 clocks using dummy bytes (0xFF)
Enable CS (low)
Send another dummy byte
Send the init command (0x40, 0x00, 0x00, 0x00, 0x00, 0x95)
Repeatedly send a dummy byte until the card replies

Another site says the CS pin should be asserted before sending the 80 clocks. This is confusing as the pin is active low. It did read as though "assert" means low but as this C example seems to be the oposite i assume it means high.

[mackrackit]

For SD card go here and look at SDFS3.zip
http://www.melabs.com/resources/samples.htm
It is so much easier than bit-banging. Added plus is the FAT16 file system.

[The Master]

Hi, Since my last post Ive been doing some testing and i actually got a PIC to read data

Ive been using the hardware SPI instead of bit-banging. Thanks for that link though because the next thing i need to do is figure out FAT16. Im working in ASM but having the example in PBP makes it easier to read :P Thanks!