ee_module.c

PIC_Hi-Tech_C_Mike_Pearces_I2C_routines Microchi PIC_Hi-Tech C_I2C_for_EEPROM_24LC01B Code

unsigned char eedata_readbyte(unsigned char addr){
  EEADR = addr;  
  EEPGD = 0;  CFGS = 0;
  RD = 1;
  return(EEDATA);
}

//non- interrupt driven writes

void eedata_writebyte(unsigned char addr, unsigned char byte){
  char istat;
  EEADR = addr;  EEDATA = byte;
  EEPGD = 0;  CFGS = 0; WREN = 1;
  istat = GIE;
  GIE = 0;
  EECON2 = 0x55;
  EECON2 = 0xAA;
  WR=1;
  GIE = istat;  // reenable interrupt
  while (WR) ;  // wait for write to complete
  EEIF = 0; WREN = 0; //clear interrupt flag, write enable
}

//Write string to DATA EEPROM
char eedata_writestr(unsigned char *s, unsigned char addr){
  char c;
  while(*s) {
    eedata_writebyte(addr,*s);
    // verify
    c = eedata_readbyte(addr);
    if (c != *s) return(1);
    addr++;
    s++;
  }
  // write end of string
  eedata_writebyte(addr,*s);
  c = eedata_readbyte(addr);
  if (c != *s) return(1);
  return(0);
}

//Read string from DATA EEPROM
unsigned char eedata_readstr(unsigned char *s, unsigned char addr, unsigned char max){
  unsigned char c,cnt;
  cnt = 0;
  do {
    c = eedata_readbyte(addr);
    addr++;
    *s = c;
    s++; cnt++;
  }while((c) && (cnt < (max-1)));
  // last byte non-zero, terminate this string
  if (c) *s = 0;
  return(addr);
}