byte MMC_ReadSector(byte *buffer, uint32_t sector)
{
if (!(_mmcState & MMC_INITED))
return MMC_NOT_INITED;
if (!(_mmcState & MMC_HIGH_DENSITY))
sector <<= 9;
MMC_SS_LOW();
if (MMC_Command(17,sector) != 0 || MMC_Token() != 0xFE)
return MMC_Release(READ_FAILED);
SPI_Receive(buffer,512); // WARNING! Will strip 2 CRC bytes as well
return MMC_Release(0);
}
byte MMC_WriteSector(byte *buffer, uint32_t sector)
{
if (!(_mmcState & MMC_INITED))
return MMC_NOT_INITED;
if (!(_mmcState & MMC_HIGH_DENSITY))
sector <<= 9;
u8 r = WRITE_FAILED;
SPI_Enable();
MMC_SS_LOW();
if (MMC_Command2(24,sector) != 0)
{
u8 d = 16;
while (d--)
SPI_ReceiveByte(0xFF); // pad
SPI_ReceiveByte(0xFE); // Send token
SPI_Send(buffer,512);
SPI_ReceiveByte(0xFF); // CRC
SPI_ReceiveByte(0xFF); // CRC
u8 status;
while ((status = SPI_ReceiveByte(0xFF)) == 0xFF)
;
if (status == 0xE5)
r = 0;
else
r = status;
while (SPI_ReceiveByte(0xFF) == 0)
;
r = MMC_Release(r);
} else {
r = MMC_Release(WRITE_FAILED);
}
return r;
}
byte MMC_Init2()
{
byte ocr[4];
MMC_SS_HIGH(); //
SPI_Init(); // Init slow at first TODO
_mmcState = 0;
// initialize the MMC card into SPI mode by sending 80 clks
int i;
for (i = 0; i < 10; i++)
SPI_ReceiveByte(0xFF);
// Send GO_IDLE_STATE
MMC_SS_LOW();
if (MMC_Command(0,0) != 1)
return GO_IDLE_TIMEOUT;
_mmcState = MMC_PRESENT;
MMC_SS_HIGH();
// Full speed
SPI_Enable();
MMC_SS_LOW();
if (MMC_ReadOCR(58,0,ocr) != 1) // Read OCR check voltages
return READ_OCR_TIMEOUT; // Can't read OCR
if ((ocr[1] & 0x10) == 0)
return BAD_VOLTAGE; // Card does not like out voltage
// Try CMD8
if (MMC_ReadOCR(8,0x1AA,ocr) == 1)
{
// SDHC
_mmcState |= MMC_SDHC;
if ((ocr[2] & 0x0F) != 1)
return BAD_VOLTAGE; // Card does not like out voltage
if (ocr[3] != 0xAA)
return BAD_PATTERN;
// Send ACMD41 and wait for it to come out of idle
i = 0x7FFF; // Wait a long time. A long, long time - some cards take 700 miliseconds or more.
while (i--)
{
MMC_Command(55,0); // SEND_APP_CMD
if (MMC_Command(41,1L << 30) == 0) // ACMD41 with HCS bit 30 set
break;
}
if (i < 0)
return OP_COND_TIMEOUT;
// Check density again
if (MMC_ReadOCR(58,0,ocr) != 0) // Bits[30:29]=1,0
return READ_OCR_TIMEOUT; // Can't read OCR
if ((ocr[0] & 0x60) == 0x40)
_mmcState |= MMC_HIGH_DENSITY;
} else {
// SDCARD 1vXX
// Send SEND_OP_COND and wait for it to come out of idle
i = 0x7FFF;
while (i--)
{
if ((MMC_Command(1,0) & 1) == 0)
break;
}
if (i < 0)
return OP_COND_TIMEOUT;
}
// Send SET_BLOCKLEN for 512 byte block
if (MMC_Command(16,512) != 0)
return SET_BLOCKLEN_TIMEOUT;
_mmcState |= MMC_INITED;
return 0;
}
