Dear Sir,
I am getting my command response some time ok and most of the time wrong.
My timing for LPSPI are accurate and checked on CRO following is my send command routine please check and suggest me any changes
//------------------- send command ---------------------
int MSD0_send_command(unsigned char cmd, unsigned int arg, unsigned char crc) {
unsigned char r1,n;
unsigned char retry;
/* Dummy byte and chip enable */
CS_LOW;
// MSD0_spi_read_write(DUMMY_BYTE);
// CS_HIGH;
// MSD0_card_enable();
/* Command, argument and crc */
// CS_LOW;
if (cmd & 0x80) { /* Send a CMD55 prior to ACMD<n> */
cmd &= 0x7F;
r1 = MSD0_send_command(CMD55, 0, 0); /* should be return 0x01 */
if (r1 > 1) return r1;
}
/* Select the card and wait for ready except to stop multiple block read */
if (cmd != CMD12) {
deselect();
if (!select()) return 0xFF;
}
MSD0_spi_read_write(cmd | 0x40);
MSD0_spi_read_write(arg >> 24);
MSD0_spi_read_write(arg >> 16);
MSD0_spi_read_write(arg >> 8);
MSD0_spi_read_write(arg);
if((cmd != CMD0) || (cmd != CMD8))
MSD0_spi_read_write(crc);
else
MSD0_spi_read_write(0x01);
// CS_HIGH;
/* Wait response, quit till timeout */
for (retry = 0; retry < 200; retry++) {
r1 = MSD0_spi_read_write(DUMMY_BYTE);
if (r1 != 0xFF) {
break;
}
}
// do {
// r1 = MSD0_spi_read_write(0xFF);
// } while ((r1 & 0x80) && --n);
// CS_HIGH;
//MSD0_spi_read_write(0xa6);
/* Chip disable and dummy byte */
//MSD0_card_disable();
// CS_LOW;
// MSD0_spi_read_write(DUMMY_BYTE);
CS_HIGH;
return r1;
}
//------------------- send command ---------------------
Arjun K
