I am using a PIC18F4550, and have implemented the following code to read/write to/from eeprom, following the asm example in the datasheet, and other examples found on this site.
The code works fine for the first write, but the verify fails on the 2nd write. (returns -2).
I assume that it is because I am not clearing a flag somewhere but am not entirely sure about this.
Thanks in advance.
Ali
The code works fine for the first write, but the verify fails on the 2nd write. (returns -2).
I assume that it is because I am not clearing a flag somewhere but am not entirely sure about this.
Code:
unsigned char readee(unsigned short address)
{
if(address > 1024 || address < 0)
return 0;
EECON1 = 0;
EEADR = (unsigned char)address;
EECON1bits.RD = 1;
return EEDATA; //Data should now be on the EEDATA register. (Only takes 1 clock)
}
unsigned char rdata;
char writeee(unsigned short address, const unsigned char data)
{
if(address > 1024 || address < 0)
return -1;
//Configuration
EECON1 = 0;
EECON1bits.WREN= 1;
EEADR = (unsigned char)address;
EEDATA = data;
DIS_INT(); //Disable interupts while writing
EECON2 = 0x55;
EECON2 = 0xAA;
EECON1bits.WR = 1;
EN_INT(); //Enabled them again now
while(!PIR2bits.EEIF); //wait until finished
EECON1bits.WREN = 0;
//Now lets perform a verify
rdata = 0;
rdata = readee(address);
if(data != rdata)
{
//Data was not written correctly.
return -2;
}
//Data written and verified correctly
return 0;
}Thanks in advance.
Ali