#define SEQ_ADR_1           ((__far volatile unsigned int*)0xFFAAAA)
#define SEQ_ADR_2           ((__far volatile unsigned int*)0xFF5554)

#define DQ7 0x0080
#define DQ5 0x0020

int fm_sectorErase(__far unsigned int *sector_adr)
{
    int flag = 0;
    // start with chip erase sequence
    FMCS_WE = 1; // set write enable flag
    *SEQ_ADR_1 = 0x00AA; // sends the command to the pointed address
    *SEQ_ADR_2 = 0x0055;
    *SEQ_ADR_1 = 0x0080;
    *SEQ_ADR_1 = 0x00AA;
    *SEQ_ADR_2 = 0x0055;
    *sector_adr = 0x0030; // erase sector at the pointed address
    while(flag == 0)
    {
        if((*sector_adr & DQ7) == DQ7) // Toggle bit
        {
            flag = 1; // successful erased
        }
        if((*sector_adr & DQ5) == DQ5) // time out
        {
            if((*sector_adr & DQ7) == DQ7)
            {
                flag = 1; // successful erased
            }
            else
            {
                flag = 2; // timeout error
            }
        }
    }
    FMCS_WE = 0; // reset write enable flag
    return(flag);
}