PIC18 EEPROM fails to write

Question

I am working on a project using a PIC18F26K20. I need to store several value in EEPROM, but it does not store any data, all I evers get back is 0xff.

Here is the code I am using:

 unsigned char ReadEEPROM(unsigned char address){
     EECON1=0;                   //ensure CFGS=0 and EEPGD=0
     EEADR = address;
     EECON1bits.RD = 1;
     return(EEDATA);
 }
void WriteEEPROM(unsigned char address,unsigned char data){
    char SaveInt; 
    SaveInt=INTCON;             //save interrupt status
    EECON1=0;                   //ensure CFGS=0 and EEPGD=0
    EECON1bits.WREN = 1;        //enable write to EEPROM
    EEADR = address;            //setup Address
    EEDATA = data;              //and data
    INTCONbits.GIE=0;           //No interrupts
    EECON2 = 0x55;              //required sequence #1
    EECON2 = 0xaa;              //#2
    EECON1bits.WR = 1;          //#3 = actual write
    INTCON=SaveInt;             //restore interrupts
    while(!PIR2bits.EEIF);      //wait until finished
    EECON1bits.WREN = 0;        //disable write to EEPROM
}

Is there something else I need to do to store Data in EEPROM? Or am I doing some thing wrong?

Answer 1

here is an example function to write to the eeprom.

void write_16f84_eeprom(unsigned char adr, unsigned char d)
{
   EEADR = adr;  // the address within the EEPROM
   EEDATA = d;   // the data to be written to that address

   WREN = 1;     // write enable
   EECON2 = 0x55; // protection sequence
   EECON2 = 0xaa;

   WR = 1;      // begin programming sequence

   // wait, in loop, for write operation to complete
   // I.E, WR control bit is 0
   //     and EEIF interrupt flag bit is 1

   WREN = 0;  // disable write enable

   // after completion of the write operation
   EEIF = 0 
}