Tiêu đề 3160712-MPI_study material.pdf ✅

SAL Engineering & Technical Institute Computer Engineering Department Microprocessor and Interfacing (3160712) Study Material Year: 2021-2022 Prepared By: Pro. Parul Oza
Arithmetic and Logical Unit(ALU) Register Array Control Unit 1. Introduction toMicroprocessor Definition: • “The microprocessor is a multipurpose, clock driven, register based, digital-integrated circuit which accepts binary data as input, processes it according to instructions stored in its memory, and provides results as output.” • “Microprocessor is a computer Central Processing Unit (CPU) on a single chip that contains millions of transistors connected by wires.” Introduction: • A microprocessor is designed to perform arithmetic and logic operations that make use of small number-holding areas called registers. • Typical microprocessor operations include adding, subtracting, comparing two numbers, and fetching numbers from one area to another. 2. Components ofMicroprocessor • Microprocessor is capable of performing various computing functions and making decisions to change the sequence of program execution. • The microprocessor can be divided into three segments as shown in the figure, Arithmetic/logic unit (ALU), register array, and control unit. • These three segment is responsible for all processing done in a computer Figure: Components of Microprocessor Arithmetic and logic unit (ALU) • It is the unit of microprocessor where various computing functions are performed on the data. • It performs arithmetic operations such as addition, subtraction, and logical operations such as OR,AND, and Exclusive-OR. • It is also known as the brain of the computer system.
Register array • It is the part of the register in microprocessor which consists of various registers identified by letters such as B, C, D, E, H, and L. • Registers are the small additional memory location which are used to store and transfer data and programs that are currently being executed. Control unit • The control unit provides the necessary timing and control signals to all the operations in the microcomputer. • It controls and executes the flow of data between the microprocessor, memory and peripherals. • The control bus is bidirectional and assists the CPU in synchronizing control signals to internal devices and external components. • This signal permits the CPU to receive or transmit data from main memory. 3. System bus (data, address and control bus). • This network of wires or electronic pathways is called the 'Bus'. • Asystem bus is a single computer bus that connects the major components of a computer system. • It combines the functions of a data bus to carry information, an address bus to determine where it should be sent, and a control bus to determine its operation. • The technique was developed to reduce costs and improve modularity. Figure: System Bus
Address Bus • It is a group of wires or lines that are used to transfer the addresses of Memory or I/O devices. • It is unidirectional. • Thewidthoftheaddressbus corresponds tothemaximum addressingcapacityofthe bus, or the largest address within memory that the bus can work with. • The addresses are transferred in binary format, with each line of the address bus carrying a single binarydigit. • Thereforethemaximumaddresscapacityisequaltotwotothepowerofthenumberof lines present (2^lines). Data Bus • It is used to transfer data within Microprocessor and Memory/Input or Output devices. • It is bidirectional as Microprocessor requires to send or receive data. • Eachwireisusedforthetransferofsignalscorrespondingtoasinglebitofbinarydata. • As such, a greater width allows greater amounts of data to be transferred at the same time. Control Bus • Microprocessor uses control bus to process data, i.e. what to do with the selected memory location. • Some control signals are Read, Write and Opcode fetch etc. • Various operations are performed by microprocessor with the help of control bus. • Thisisadedicatedbus,becausealltimingsignalsaregeneratedaccordingtocontrolsignal. 4. Microprocessor systems withbusorganization Figure: Microprocessor systems with bus organization
• To design any meaningful application microprocessor requires support of other auxiliary devices. • In most simplified form a microprocessor based system consist of a microprocessor, I/O (input/output) devices andmemory. • These components are interfaced (connected) with microprocessor over a common communication path called system bus. Typical structure of a microprocessor based system is shown in Figure. • Here, microprocessor is master of the system and responsible for executing the program and coordinating with connected peripherals as required. • Memory is responsible for storing program as well as data. System generally consists of two types of memories ROM (Read only and non-volatile) and RAM (Read/Write and volatile). • I/O devices are used to communicate with the environment. Keyboard can be example of input devices and LED, LCD or monitor can be example of output device. • Depending on the application level of sophistication varies in a microprocessor based systems. For example: washing machine, computer.