PIC16F877A-HITECH C- EEPROM

EEPROM

Steps to ------Read

1.     Specify the memory location in EEADR (EEADR=4;)

2.     Clear the EEPGD bit (EEPGD=0 ;)

3.     Read the value from EEDATA register (unsigned short int a =EEDATA ;)

Steps to ------Write

1.     Specify the memory location in EEADR (EEADR=4;)

2.     Write the value to EEDATA register (EEDATA=7;)

3.     Set WREN (WREN=1;)

4.     Clear the EEPGD bit (EEPGD=0 ;)

5.      Write 55h to EECON2  (EECON2=0x55;)

6.      Write AAh to EECON2  (EECON2=0xAA;)

7.     Set the WR bit (WR=1;)

#include<pic.h>
#define  _XTAL_FREQ 16000000
__CONFIG(0x3f7a);
unsigned short int eeread();
eewrite(unsigned short int ,unsigned short int );

main()
{
eewrite(4,'1');
unsigned short int a=eeread(); //data from eeprom
TRISB=0;
PORTB=a;
while(1) ;
}  

unsigned short int eeread()
{
EEADR=4;
EEPGD=0;
unsigned short int z =EEDATA;
return z;
}

eewrite(unsigned short int x,unsigned short int y)
{
EEADR=x;
EEDATA=y;
WREN=1;
EEPGD=0 ;
EECON2=0x55;
EECON2=0xAA;
WR=1;
}