SD card initialization using SPI interface
- by Tobias
I get invalid response Codes from my SD Card(CMD8, CMD55, CMD41)
Init routine:
SDCS = 1; // MMC deaktiviert
SPI1CON1bits.SMP = 0;
SPI1CON1bits.CKE = 1;
SPI1CON1bits.MSTEN = 1;
SPI1CON1bits.CKP = 0;
SPI1STATbits.SPIEN = 1;
for(i=0;i<10;i++) SPI(0xFF);
// RESET
unsigned char rr=Command(CMD0,0);
SDCS=1; // MMC deactivated
/*OK response == 1*/
r=Command(CMD8,0); // check voltage
SDCS=1;
/*
response == 0xC1 ?!?
*/
r = Command(CMD58,0); // READ_OCR
unsigned char ocr1 = SPI(0xFF);
unsigned char ocr2 = SPI(0xFF);
unsigned char ocr3 = SPI(0xFF);
unsigned char ocr4 = SPI(0xFF);
unsigned char ocr5 = SPI(0xFF);
/*
r = 0xF8; ?!?
ocr1 = 0x0F;
ocr2 = 0xFF;
ocr3 = 0xFF;
ocr4 = 0xFF;
ocr5 = 0xFF;
*/
SDCS=1;
// INIT
unsigned char rrr = 0;
i=10000;
do
{
rrr=Command(55,0); // Next is APP CMD
SDCS=1;
if(r)
break;
}while(--i>0);
/*
OK response == 1
*/
// APP CMD 41 with OCR = 0x0F??
You can read the response codes in the comments.
Is it possible the response code to CMD8 is 0xC1? Bit 7 should be 0, right?
Is it a hardware error?
