EEPROM for PIC

EEPROM read/write example for the PIC12F629 and PIC12F675 using MikroC PRO.

Overview

This repository contains a simple and didactic example of how to access the internal data EEPROM of the PIC12F629 and PIC12F675.

The project provides reusable routines for:

• writing one byte to EEPROM
• reading one byte from EEPROM
• validating the EEPROM address range

It is intended as a basic embedded systems example for students, hobbyists, and developers working with PIC microcontrollers.

Platform and Development Environment

• Microcontrollers: PIC12F629, PIC12F675
• Language: C
• IDE: MikroC PRO v7.2.0
• Clock: 4 MHz

EEPROM Information

The PIC12F629 and PIC12F675 provide:

• 128 bytes of internal data EEPROM
• valid address range from 0x00 to 0x7F

Project Structure

src/

• main.c — example application using the EEPROM routines
• eeprom.c — EEPROM implementation
• eeprom.h — EEPROM public interface

docs/

• PIC12F629.pdf — microcontroller documentation

Features

• EEPROM byte write routine
• EEPROM byte read routine
• address limiting to valid EEPROM range
• write status return for error handling
• reusable module split into .h and .c

How It Works

write(unsigned char data, unsigned char address)

Writes one byte to the selected EEPROM address:

• validates the address range
• selects data EEPROM access
• enables write mode
• temporarily disables global interrupts
• performs the required unlock sequence
• starts the write cycle
• waits until the write operation finishes
• returns a status code

read(unsigned char address)

Reads one byte from the selected EEPROM address:

• validates the address range
• selects data EEPROM access
• loads the EEPROM address
• starts the read cycle
• returns the byte stored in EEDAT

Example Usage

#include "eeprom.h"

void main()
{
    unsigned char value;
    unsigned char status;

    status = write(0x2A, 0x10);

    if (status == EEPROM_WRITE_OK)
    {
        value = read(0x10);
    }

    while (1)
    {
    }
}

Return Values

write(...)

• EEPROM_WRITE_OK → write completed successfully
• EEPROM_WRITE_ERROR → write operation failed

Address Range

This implementation supports EEPROM addresses in the following range:

• 0x00 to 0x7F

If an address above the valid range is passed, it is limited to the maximum valid EEPROM address.

Author

Daniel Gier Arndt

This project is a small embedded systems study/example repository focused on EEPROM access with the PIC12F629 and PIC12F675.