// FROM SPEC...
Uint64 a0_long_checksum =0;
Uint64 a0_long_checksum01 =0;
Uint64 a0_long_checksum23 =0;

void calculate_checksum(register Uint32 *start_address, register Uint32 *end_address)
{
    Uint64 lcs = a0_long_checksum; //use local register variable for speed?? TAW not sur that works

    while(start_address < end_address)
    {
        lcs = lcs + *start_address ;
        lcs = lcs + (Uint32)*(start_address + 1) ;
        start_address = start_address + 2;
    }
    a0_long_checksum = lcs;
}


void Pflash_GetChecksum01(void)
{
    a0_long_checksum = 0;
    Uint32* start_address = (Uint32*) PGM_BLOCK0_ADDRESS; // 0x00000000
    Uint32* end_address = (Uint32*) (PGM_BLOCK2_ADDRESS -8);// 0x00010000 - 8
    calculate_checksum(start_address,end_address ); // result is in a0_long_checksum
    a0_long_checksum01 =a0_long_checksum;
}