EEPROM issue PIC18f4520

HI,

earlier i had a function for reading/writing into internal EEPROM for PIC18F4480.

When i switched to PIC18F4520, the code is not working anymore.

From the datasheet of PIC18F4520 it says:

MOVLW DATA_EE_ADDR ;
MOVWF EEADR ; Data Memory Address to read
BCF EECON1, EEPGD ; Point to DATA memory
BCF EECON1, CFGS ; Access EEPROM
BSF EECON1, RD ; EEPROM Read
MOVF EEDATA, W ; W = EEDATA

Click to expand...

from which i wrote the following C function:

unsigned char EEPROM_read(unsigned char eeprom_addr)
{
EEADR = eeprom_addr;
EECON1bits.EEPGD = 0;
EECON1bits.CFGS = 0;
EECON1bits.RD = 1;
return EEDATA;
}

Click to expand...

can anyone please guide what can i be doing wrong here?

I can't see anything wrong with your code. The only reason I can think of why this would not work is if a previous write hadn't finished, try adding while(EECON1bits.WR); to the start of your code.

Mike.

Thank you Pommie for the suggestion, i tried it and it but the problem still exists. However i noticed that if i comment everything in my main() function, it is still giving errors.

Attached is the errors (warnings) from simulation.

Can it be that i have to setup some register in main function.

It is giving all these errors even with main function such as

void main(void)
{
}

oops sorry, its working now. There was some problem with the configuration of the PIC. Clock frequency.