01 Introduction to Microprocessor

Odd semester

2013/2014

Mikroprosesor&Mikrokontroler

THE MICROPROCESSOR-

BASED PC SYSTEM

Prima Dewi Purnamasari

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What is Computer?

Basically, there are 3 components to build a

computer, and those three are interconnected

with wires. Could you name it?

2

? ? ?

Most of picture and tables in this slide are taken from “The Intel

Microprocessors 8086/8088, 80186/80188, 80286, 80386, 80486, Pentium,

Pentium Pro Processor, Pentium II, Pentium III, Pentium IV Architecture,

Programming, and Interfacing”, Seventh Edition, Brey, Barry, B., PHI Inc,

USA, 2006

General Block Diagram of the PC 3

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BUS

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Microprocessor 5


The Microprocessor

The microprocessor is the controlling element in

a computer system and is sometimes referred to

as the CPU (Central Processing Unit)

Memory and I/O are controlled through

instructions that are stored in the memory and

executed by the microprocessor

6


The Microprocessor

The microprocessor performs three main tasks

for the computer system:

Data transfer between itself and the memory or I/O

systems

simple arithmetic & logic operations (Table 1.3)

program flow via simple decisions (Table 1.4)

7

Sample of arithmetic and logic operations

8

Common flags that are tested before making program decision

Common flags 9


The Microprocessor

Why the microprocessor is powerful?

Able to execute millions of instructions per second

from a program or software (group of instructions)

stored in the memory system

Able to make simple decision, based upon numerical

facts (slide pg.9)

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Memory 11


Memory

The memory system is divided into three main

parts:

TPA (Transient Program Area)

system area,

XMS (Extended Memory System) (optional)

12


Memory System

The first 1M byte of memory the

real/conventional memory system. Intel mP is

designed to function this area in real mode of

operation

80286 Pentium 4 contain not only real

memory, but also extended memory

The Pentium Pro-based computer system, for

example, can have up to 1M less than 4G or 1 M

less than 64G of extended memory

13


Memory Address

In Hexadecimal format

1M Byte Real Memory:

= 220 x 1 Byte

= 1 0000 0000 0000 0000 0000 B x 1 Byte

Each block of memory holds 1 Byte (8 bits) data

1MByte memory address:

Starting address (#1) : 00000H

Ending address (#220) : FFFFFH

14


Trivia

How if 2MByte Memory? What is the starting and

ending address?

Answer:

2MB = 221

= 1 1111 1111 1111 1111 1111 (write 21 x 1)

= 1FFFFF H

Thus:

Starting address = 000000H

Ending address = 1FFFFFH

15


Memory Illustration

FFFFFH …

………

…

…

………

…

…

………

…

…

00002H …

00001H 0111 0001 B

00000H 0AH

16

Each block of memory contains 1 Byte or 8 bits data

Division of the first 1MB (real) memory

Memory System 17


Transient Program Area (TPA)

Holds the OS and other program that control the

computer system

Stores any currently active or inactive

application programs

The length of TPA is 640 KB

18


Memory map of TPA

The memory

map (fig. 1.4,

in

hexadecimal

addr.) shows

how many

areas of the

TPA are used

for system

programs,

data, and

drivers

19


TPA

The interrupt vectors access various features of

the DOS, BIOS (Basic I/O System), and

application

The BIOS and DOS communications areas contain

transient data used by program to access I/O

devices and internal features of the computer

system

20


TPA

The IO.SYS is a program that loads into the TPA

from the disk whenever an MSDOS or PC DOS

system is started

The MSDOS (PCDOS) program occupies two areas

of memory

The size of the driver area and # of drivers

change from one computer to another

21


TPA

The COMMAND.COM program controls the

operation of the computer from the keyboard

when operated in DOS mode

The free TPA area holds application programs as

they are executed

22


System Area

The system area

contains program on

either a read-only

memory or flash

memory and also

areas of read/write

(RAM) memory for

data storage

23


EMS

The area at locations

C8000H-DFFFFH is

often open or free

Expanded Memory

System (EMS)

EMS allows a 64 KB

page frame of

memory to be used

by application

programs

24


I/O 25


Input Output (I/O)

I/O space: port 0000H to port

FFFFH.

An I/O port is similar to a

memory address but addresses

an I/O device

The I/O area contains two

major sections

below I/O 0500H system devices

the remaining area for

expansion

26


BUS 27


Buses

A bus is a set of common connections (wires )

that interconnect components in a computer

system and carry the same type of information

Function:

select an I/O or memory device

transfer data between an I/O device or memory and

the microprocessor

control the I/O and memory system

28

Three buses exist for the transfer of information:

• address,

• data,

• control

BUSSES 29


Buses

1. Control bus

Select the memory or I/O and cause them to

perform a read or write operation.

MRDC, MWTC, IORC, IOWC

2. Address bus

Requests a memory location or an I/O location

3. Data bus

To send data to or from microprocessor

30


Example the micro-instructions for READ

1. The p reads the contain of memory location

by sending the memory an address through

address bus

2. The p sends the memory read control signal

(MRDC) to cause memory to read data via

control bus

3. The data read from the memory are passed to

the microprocessor through the data bus

31


Buses’ size

Data bus size defines the amount of data can be

transferred at a time (8, 16, 32, 64 bit)

Address bus size corresponds to (maximum)

memory size can be attached to the

microprocessor

32

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Self reading…

Review from Fundamental of Digital Systems

Number systems 34


Reference/Text Book

“The Intel Microprocessors”, 8th Edition, Brey,

Barry, B., Prentice Hall, USA, 2009

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Documents

01 Introduction to Microprocessor