WEEK 5

LITERATURE REVIEW

This chapter discusses about the theory and software that are use in the project. There are three main theories in this project that are the theories of microcontrollers, Proteus VSM 7.0 and also PICC Lite Compiler.

Microcontroller

        Microcontrollers can be found in any products these days. For example modern washing machine in our house that consists of timer, button and LED contains a microcontroller. All modern cars contain microcontroller. Digital electronics knowledge is essential in order to understand the way microcontroller works. However, with the existing of latest microcontroller like PIC16F877A from

microchip, microcontroller works by writing programming code using C  programming language. Everything becomes so simple by learning C programming and uses it to program the microcontroller.

Here are the examples of microcontrollers:

( i ) PIC 16F870

( ii ) PIC 16F871

( iii ) PIC 16F872

( iv ) PIC 16F873A

( v ) PIC 16F874A

( vi ) PIC 16F876A

( vii ) PIC 16F877A

What is a Microcontroller?

A microcontroller is a small computer and it can only perform simple task.

Microcontroller consists of:

• Processor that executes programs. Processor execute program digitally. All instruction given to the processor should be in digital form.
• Program Memory to store the program that has been compiled successfully by the programmer. 
• RAM (random-access memory) to store "variables." 
• IO Port to connect sensor, keypad, LED, Relay and so on. 
• Timer to count the time to execute some process.

Microchip PIC 16F877A Microcontroller Features

Figure 2.1: PIC 16F877A

High-Performance RISC CPU :-

• Lead-free; RoHS-compliant

• Operating speed: 20 MHz, 200 ns instruction cycle

• Operating voltage: 4.0-5.5V

• Industrial temperature range (-40° to +85°C)

• 15 Interrupt Sources

• 35 single-word instructions

• All single-cycle instructions except for program branches (two-cycle)