Walter Torresani

How can i write multiple data to MC9S08SH8 flash's?

Discussion created by Walter Torresani on Apr 1, 2008
Latest reply on May 2, 2009 by Ellen Timiney
I've some problem to write datas to flash of the SH8. I've made this function to write one byte in to the flash on a specified (empty) address:
unsigned int write_flash(unsigned int indirizzo,byte dato){  
    while(!FSTAT_FCBEF);  //wait if there's another command in progress
      FSTAT_FACCERR = 1;
    (*((volatile unsigned char *)(indirizzo))) = dato;    //write dato in the location defined by indirizzo
    FCMD = 0x20;          // write byte command
    FSTAT_FCBEF = 1; //Send Command
    _asm NOP;        //Wait 4 cycles
    _asm NOP;
    _asm NOP;
    _asm NOP;
    _asm NOP;
    return(indirizzo);           //return indirizzo to verify if the write location is correct
In the main program I want to made a firmware to write once the flash to store some important data like firmware version and some costant, that are useful for the execution of the main alghoritm and then I want to protect this data forever.
My problem is that: when i call multiple times the write flash function, only the firts call work fine.
 address = write_flash(0xEA01,0x10); //this instruction produce the wanted effect
 address = write_flash(0xEA02,0x01); // this instruction doesn't work       
 address = write_flash(0xEA03,0x03); // and also this doesb't work
How can I write multiple locations of the flash in sequence, for instance with a for cycle.
Thak for your help,