u08 mmcRead(u32 sector, u08* buffer)
{
u08 r1;
u16 i;
// assert chip select
cbi(MMC_CS_PORT,MMC_CS_PIN);
// issue command
r1 = mmcCommand(MMC_READ_SINGLE_BLOCK, sector<<9);
#ifdef MMC_DEBUG
rprintf("MMC Read Block R1=0x%x\r\n", r1);
#endif
// check for valid response
if(r1 != 0x00)
return r1;
// wait for block start
while(spiTransferByte(0xFF) != MMC_STARTBLOCK_READ);
// read in data
for(i=0; i<0x200; i++)
{
*buffer++ = spiTransferByte(0xFF);
}
// read 16-bit CRC
spiTransferByte(0xFF);
spiTransferByte(0xFF);
// release chip select
sbi(MMC_CS_PORT,MMC_CS_PIN);
// return success
return 0;
}
u08 mmcSendCommand(u08 cmd, u32 arg)
{
u08 r1;
// assert chip select
cbi(MMC_CS_PORT,MMC_CS_PIN);
// issue the command
r1 = mmcCommand(cmd, arg);
// release chip select
sbi(MMC_CS_PORT,MMC_CS_PIN);
return r1;
}
u08 mmcSendCommand(u08 cmd, u32 arg)
{
u08 r1;
u16 wait = 0;
// assert chip select
_mmcEnableCS();
spiTransferByte(0xFF);
// issue the command
r1 = mmcCommand(cmd, arg);
// release chip select
while (wait < 1900) {
wait++;
}
_mmcDisableCS();
return r1;
}
u08 mmcWrite(u32 sector, u08* buffer)
{
u08 r1;
u16 i;
// assert chip select
cbi(MMC_CS_PORT,MMC_CS_PIN);
// issue command
r1 = mmcCommand(MMC_WRITE_BLOCK, sector<<9);
#ifdef MMC_DEBUG
rprintf("MMC Write Block R1=0x%x\r\n", r1);
#endif
// check for valid response
if(r1 != 0x00)
return r1;
// send dummy
spiTransferByte(0xFF);
// send data start token
spiTransferByte(MMC_STARTBLOCK_WRITE);
// write data
for(i=0; i<0x200; i++)
{
spiTransferByte(*buffer++);
}
// write 16-bit CRC (dummy values)
spiTransferByte(0xFF);
spiTransferByte(0xFF);
// read data response token
r1 = spiTransferByte(0xFF);
if( (r1&MMC_DR_MASK) != MMC_DR_ACCEPT)
return r1;
#ifdef MMC_DEBUG
rprintf("Data Response Token=0x%x\r\n", r1);
#endif
// wait until card not busy
while(!spiTransferByte(0xFF));
// release chip select
sbi(MMC_CS_PORT,MMC_CS_PIN);
// return success
return 0;
}
u08 mmcWrite(u32 sector, u08* buffer)
{
u08 r1;
u16 i;
u16 retries;
spiSetClockPhase(SD_CLOCK_PHASE);
spiSetBitrate(SD_TRANSFER_SPI_DIV);
// assert chip select
_mmcEnableCS();
retries = 0;
// wait for card not busy, at most 250ms
if (cardBusy) {
spiTransferByte(0xFF);
do {
r1 = spiTransferByte(0xFF);
retries++;
if (!r1) {
delay_us(250);
}
else
break;
}
while (!r1 && retries < 0xFFE);
}
if (retries == 0xFFE) {
_mmcDisableCS();
rprintf("mmcWrite - card still busy, sector ");
rprintfu32(sector);
rprintfCRLF();
return -1;
}
// issue command
r1 = mmcCommand(MMC_WRITE_BLOCK, sector<<9);
#ifdef MMC_DEBUG
//rprintf("MMC Write Block R1=0x%x\r\n", r1);
#endif
// check for valid response
if(r1 != 0x00) {
_mmcDisableCS(); // Andreas - was reversed
rprintf("mmcWrite - invalid response %x\r\n",r1);
return r1;
}
// send dummy
spiTransferByte(0xFF);
// send data start token
spiTransferByte(MMC_STARTBLOCK_WRITE);
// write data
for(i=0; i<0x200; i++)
{
spiTransferByte(*buffer++);
}
// write 16-bit CRC (dummy values)
spiTransferByte(0xFF);
spiTransferByte(0xFF);
// read data response token
r1 = spiTransferByte(0xFF);
if( (r1&MMC_DR_MASK) != MMC_DR_ACCEPT) {
_mmcDisableCS();
return r1;
}
#ifdef MMC_DEBUG
//rprintf("Data Response Token=0x%x\r\n", r1);
#endif
/* old busy code
// wait until card not busy
while(!spiTransferByte(0xFF));
*/
// Provide card with 8 clock cycles to complete the operation
spiTransferByte(0xFF);
cardBusy = 1;
// release chip select
_mmcDisableCS();
// return success
return 0;
}
