The disk_writep function writes data to the sector.
DRESULT disk_writep ( BYTE* buff, /* [IN] Pointer to the data to be written */ DWORD sc, /* [IN] Sector number or Number of bytes to wtite */ );
A sector write operation is done in following sequence.
If a write transaction is in progress, disk_readp() function will fail and disk_initialize() function finalize the current write transaction.
This funciton is needed when _USE_WRITE == 1.