Introduction to Microprocessors Manijeh Keshtgary Fall 2006 Shiraz University of Technology

What is Computer Data Processing Data Storage

Major Components of a Computer I/O MEMORY CPU SYSTEM BUS

What is CPU CPU

What is CPU? Control Unit & Instruction Decoder Arithmetic/Logic Unit Registers The Central Processing Unit (or  P)

Speed of CPU based on It’s Clock Format of an instruction Parallel nature of instruction execution Access time to its memory & I/O

Memory Two different types of information stored in memory –Instruction –Data Example: Adding 2 numbers, addition operation is an instruction and the actual numbers are data

I/O Input Device : transfers outside information into computer Ex: keyboard, mouse, scanner, camera…. Output device: allows computers to inform their internal states & data to the outside world. Ex: Monitor, speakers, printers……

Buses Think of them as roads that connect different parts of a computer 3 types of Buses –Address Bus –Data Bus –Control Bus

Address Bus Carry the CPU generated address out to memory & I/O devices It is unidirectional and only travel outward from CPU No. of address lines that a microprocessor has determines the size of the memory space that it can access

Memory size

Data Bus These are the data signals that travel out of and into the  P (bi-directional). The number of wires in the data bus depends on the word size that the  P operates with. An 8-bit  P will have a data bus consisting of 8 wires and a 32-bit  P will have a data bus with 32 wires.

Control Bus The control bus consists of wires, some of which carry signals from the CPU to external devices, while others carry signals from external devices to the CPU. The number of wires present in the control bus varies from one  P to another. Examples of control bus signals are READ, WAIT.

Cache Faster but smaller memory type. Small so reduce the memory access latency Ex: A library with a person behind the desk (LE) (he is responsible to give you the book you want). you will read the book it the library and return it. Customer A ask for book A. LE gets the book from store room, returns to counter and give it to him.customer A will return the book in few minutes. So LE goes to storeroom,…. Customer B comes and ask for book A LE goes to storeroom……. Is there a way to improve the performance????

Cache Yes, we can give LE a backpack to store the last 10 books that customers return The backpack is a cache for this system! If the data is not is cache (cache miss), are we wasting time??? We can have 2 level cache. Main memory is much larger than cache

Microprocessor, Microcomputer and microcontroller  P : CPU unit packaged in a single chip. Ex: Intel Pentium family Microcomputer : A computer that uses  P as its CPU. Ex: PC  C created by packaging CPU, Memory and I/O parts and buses in a single VLSI chip.

Two classes of Computers General Purpose Computer System (GPCS): Example: Desktop and Laptop In this type of computer many different software can be installed and run to do many different jobs. Example, MSWord software does the word-processing job Application Specific Computer (ASC) Also called Embedded System) Example: Computer used in mobile telephone, video camera and many other intelligent electronic devices In this type of computer a specific software runs all the time and does a single specific job. An ASC is very small in size (typically, just a small PCB and few ICs).  C is the main IC in embedded system

What is Microcontroller

Embedded system Microcontroller

General Structure of  C

Microcontroller advantages I/O interfacing issue is greatly simplified. External memory is no longer needed for many applications. System design time is greatly shortened.