The Microcomputer System In this presentation you will: Investigate the microprocessor Title Page

The Microcomputer System Microprocessors can be found in practically every electronic consumer product. Next > Every computer, mobile phone, automobile, microwave or television has at least one microprocessor inside it. Introduction

The Microcomputer System Microprocessors contain integrated circuits. The packaging protects the delicate IC, and helps draw heat away from it. Next > The integrated circuit (IC) is encased in a protective package. The integrated circuit is connected to legs or pins, which connect the microprocessor to other electronic devices in the system. Introduction

The Microcomputer System Next > Integration The Microprocessor operates as part of a complete system called a microcomputer. The system includes other integrated circuits such as memory devices. The integrated circuits that support the microprocessor (memory, input/output interface etc.) are called support chips. Without them the system would not operate. Microprocessor Other Support Chips Memory

The Microcomputer System The elements of a basic microcomputer system can be shown as functional blocks on a block diagram. Next > Control bus Data bus Address bus Signal connections between the microprocessor and the support devices are achieved using three buses: Elements of the System The arrows indicate the direction of data travel on each bus. Control Bus Data Bus Address Bus MicroprocessorMemory Input/Output Interface

The Microcomputer System The microprocessor contains various registers, an Arithmetic Logic Unit, and a Control Unit. Next > The microprocessor is connected to the support devices through: Inside a Microprocessor Control bus Data bus Address bus Control Unit System Clock Registers Arithmetic Logic Unit Internal Data Bus Internal Control Bus Microprocessor Buffer Address Bus Data Bus Control Bus

The Microcomputer System Next > The Arithmetic Logic Unit (ALU) is the part of the processor that performs the maths. It adds and compares numbers. ALU (Arithmetic Logic Unit) All the logic and arithmetic functions are carried out here. Control Unit System Clock Registers Arithmetic Logic Unit Internal Data Bus Internal Control Bus Microprocessor

The Microcomputer System The purpose of the control unit is to organise the operation of the processor, synchronising the other internal components and external support chips. Next > Control Unit It makes sure everything happens at the right time, in the right order. Control Unit System Clock Registers Arithmetic Logic Unit Microprocessor

The Microcomputer System Registers are tiny amounts of short-term storage inside the microprocessor. Next > One example is the accumulator, used to store the answer to a simple calculation. Registers Control Unit System Clock Registers Arithmetic Logic Unit Microprocessor

The Microcomputer System The Address, Data and Control bus connections are made to the microprocessor through its pins or legs. Next > Power Supply Inputs Address Bus Control Bus Data Bus Power supply connections are also made in this way. Buses

The Microcomputer System As well as a microprocessor, a microcomputer requires: A) An on/off switch B) Memory and an Input/Output Interface C) A video output device D) A keypad to allow data entry Question 1

The Microcomputer System What is the function of the ALU? A) Controlling the flow of data on the buses B) Arithmetic and logic operations C) Memory allocation and control D) Organising and synchronising the operation of the CPU Question 2

The Microcomputer System Memory provides a place to store programs. Next > There are actually two types of memory commonly used in a microcomputer, one called ROM and the other called RAM. With ROM, data is permanently stored in the locations. The microprocessor can only retrieve the data from ROM. Memory Control Bus Data Bus Address Bus Microprocessor Memory Input/ Output Interface Control Bus Data Bus Address Bus Microprocessor ROMRAM Input/ Output Interface Control Bus Data Bus Address Bus Microprocessor ROMRAM Input/ Output Interface

The Microcomputer System Read Only Memory (ROM) is an integrated circuit. Its legs or pins provide it with power and enable connection to the buses from the microprocessor. Next > From the outside, ROM may look similar to the microprocessor or any other integrated circuit, but inside it is totally different. Power Supply Inputs Address Bus Control Bus Data Bus This type of memory is commonly used to hold instructions of a program for the microcomputer to use over and over again. Read Only Memory

The Microcomputer System For example, a washing machine will have ROM as part of its microcomputer. Next > The ROM has been pre-programmed by the manufacturer with the instructions needed for the washing sequence. When the washing machine is turned on again, the instructions for the washing sequence will still be there in ROM. Data stored inside ROM is not lost when the power is turned off. Read Only Memory

The Microcomputer System With Random Access Memory (RAM), data can be both stored (write data to memory) and retrieved (read data from memory) by the microprocessor. Next > While power is supplied the contents of RAM remain. When the power is removed, the contents of RAM are lost. Control Bus Data Bus Address Bus Microprocessor ROMRAM Input/ Output Interface Random Access Memory

The Microcomputer System RAM is in an integrated circuit, its pins provide it with power and enable connection to the microprocessor buses. Next > Power Supply Inputs Address Bus Control Bus Data Bus Like ROM, the RAM integrated circuit looks the same as other integrated circuits from the outside, but inside it is different. Random Access Memory

The Microcomputer System The microprocessor can read data from, and write data to RAM. Next > RAM is commonly used as a temporary storage area of program data. For example, a calculator has RAM which temporarily stores numbers that are part of a calculation. The microprocessor can only read data from ROM. Random Access Memory Microprocessor ROMRAM I/O Interface Control Bus Data Bus Address Bus Output Input

The Microcomputer System When power is removed, data in ROM is lost. Is this statement true or false? Answer True or False. Question 3

The Microcomputer System Which of the following statements is NOT true about RAM. A) The microprocessor can change data stored there. B) The data is lost when the power is removed. C) It can be used to read data from external devices. D) The microprocessor can read data stored in RAM. E) Electrical connections are made through pins or legs. Question 4

The Microcomputer System Next > Input / Output Interface Microprocessor RAMROM Input / output Interface Control Bus Data Bus Address Bus Output Input Power Supply Inputs Address Bus Control Bus Data Bus Input Interface Output Interface The I/O interface is an integrated circuit that enables the microcomputer to control devices outside the microcomputer. An important element of the microcomputer is the input/output (I/O) interface.

The Microcomputer System The I/O interface can be divided into two sections, input interface and output interface. Next > The output interface can output signals to devices outside the microcomputer. Input / Output Interface Microprocessor RAMROM Output Interface Input Interface Control Bus Data Bus Address Bus Output Input I/O

The Microcomputer System The address bus carries signals that control where the data comes from, or goes to. Next > Address Bus MicroprocessorROMRAM Input / Output Interface Address Bus Control Bus Data Bus

The Microcomputer System The control bus carries commands from the microprocessor and returns status signals from the devices. Next > Control bus MicroprocessorROMRAM Input / Output Interface Address Bus Control Bus Data Bus

The Microcomputer System The data bus carries the data between parts of the microprocessor, and with other devices. Next > Data Bus Data from the keypad is carried to the microprocessor along the data bus. MicroprocessorRAMROM Output Interface Input Interface Address Bus I/O Control Bus Data Bus

The Microcomputer System What does the I/O interface enable control of? A) The values of data stored in memory B) The way the microprocessor works C) Devices outside the microcomputer D) RAM and ROM Question 5

The Microcomputer System Next > This enables the microprocessor to activate the signals it generates internally at the appropriate times. System Clock The system clock is an oscillator circuit. It provides the clock circuit with a regular 'heartbeat'. Control Unit System Clock Accumulator Arithmetic & Logic Unit Microprocessor The system clock enables the microprocessor to perform millions of operations every second.

The Microcomputer System The system clock enables the microprocessor to: A) Store data in memory B) Generate signals at the appropriate time C) Control keyboard inputs D) Relay address signals Question 6

The Microcomputer System In this presentation, you have seen: The main components of a microprocessor, arithmetic logic unit, register and control unit. How a microprocessor communicates with the outside world. The function of the data, address and control buses. End > Summary