Introduction

  • Introduction to microcontroller PIC18F4550
  • Programming with CCS C Compiler
  • Proteus Schematic
  • Activity 1. Turn ON/OFF four LEDs Seven
  • Activity 2. Turn ON/OFF LEDs every 500 ms
  • Activity 3. Rotate left the contents of PORTB
  • Activity 4. Create a moving dot with LEDs

(60 minutes)


Introduction to microcontroller PIC18F4550

What is a  Microprocessor

A Central Processing Unit in one chip


What is a Microcontroller

Microcontroller is a chip which contains:

  1. CPU (Central Processing Unit)
  2. Input and Output modules
  3. Program and data memory
  4. Other modules like A/D converters etc
Shortly is a full computer system in one chip, such as PIC18F4550




Program Memory: 32 K (215)

Address range: 000000 to 007FFFh

16 bit registers

Data Memory: 2 K

Address range: 000 to 7FFh

8 bit registers




The data memory of the microcontroller PIC18F4550 is 2KB

Attention   210  =1024 =1K (when we refer to memories 1K=1024)

                    220 =1Κ Χ1Κ =1 Μ          (=1 048 576 memory positions)

                    230 =1Κ Χ1Κ Χ1Κ = 1G    (=1 073 741 824  memory positions)

Attention! Also the memory positions at addresses from FF6h to FFFh are used. This memory positions are called Special Function Registers (SFR). The words that are stored to the special Function Registers are used for a special function to the microcontroller.


The program memory address bus is 16 bit. 16 bit are transfered simultaneously from the program memory to the CPU. The instructions in machine code are, with a few exceptions, 16 bit words



The values placed at the PORTB Direction Register define which pins will be inputs and which will be outputs.

1 => The correspondent pin of PORTB will be input.

0 => The correspondent pin of PORTB will be output.