SDC_Error MediaInitialize(SDCSTATE *Flag)
{
word timeout;
SDC_Error status = sdcValid, CSDstatus = sdcValid;
SDC_RESPONSE response;
// clear out flags
Flag->_byte = 0x0;
SDC_CS = 1; //Initialize Chip Select line
// This function was called for a reason Turn it on
//SDC_ON;
//Media powers up in the open-drain mode and cannot handle a clock faster
//than 400kHz. Initialize SPI port to slower than 400kHz
OpenSPI(SPI_FOSC_64, MODE_11, SMPMID);
// let the card power on and initialize
Delayms(100);
//Media requires 80 clock cycles to startup [8 clocks/BYTE * 10 us]
for(timeout=0; timeout<20; timeout++)
mSend8ClkCycles();
SDC_CS = 0;
Delayms(20);
timeout = 0xFFF;
do
{
response = SendSDCCmd(GO_IDLE_STATE,0x0);
timeout--;
}while((response.r1._byte&0x01)== 0x00 && timeout != 0);
// see if it failed
if(timeout == 0)
{
status = sdcCardInitTimeout; // we have not got anything back from the card
goto InitError;
}
timeout = 0xFFF;
do
{
response = SendSDCCmd(SEND_OP_COND,0x0);
timeout--;
}while((response.r1._byte&0x01)== 0x01 && timeout != 0);
// see if it failed
if(timeout == 0)
{
status = sdcCardInitTimeout; // we have not got anything back from the card
goto InitError;
}else{
// get the CSD register before increasing the spped page 4-8 of sd card manual last line
CSDstatus=CSDRead();
if(!CSDstatus)
OpenSPI(SPI_FOSC_4, MODE_11, SMPMID); //Increase clock speed
else
status=sdcCardTypeInvalid;
}
// Turn off CRC7 if we can, might be an invalid cmd on some cards (CMD59)
// response = SendMMCCmd(cmdCRC_ON_OFF,0x0);
// Ok Now set the block length to 512. It should be already
SendSDCCmd(SET_BLOCKLEN,BLOCKLEN_512);
// set the write protect state
if(IsWriteProtected())
Flag->isWP = TRUE;
// read it a couple times until we sucessfully read it, seen san disks that really do not
// like this init routine for somereason, almost have to prime the device...
for(timeout = 0xFF; timeout > 0 && SectorRead(0x0,(byte*)msd_buffer)!= sdcValid; timeout--)
{;}
// see if we had an issue
if(timeout == 0)
{
status = sdcCardNotInitFailure;
goto InitError;
}
return(status);
InitError:
SDC_CS = 1; // deselect the devices
return(status);
}//end MediaInitialize
