Introduction to Microprocessors
Gursharan Singh Tatla
mailme@gursharansingh.in
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Introduction to Microprocessors
The microprocessor is one of the most important
components of a digital computer.
It acts as the brain of the computer system.
As technology has progressed, microprocessors
have become faster, smaller and capable of doing
more work per clock cycle.
Sometimes, microprocessor is written as
µP.
( µ is pronounced as Mu )
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Introduction to Microprocessors
Definition:
Microprocessor is the controlling unit or CPU of a
micro-computer, fabricated on a very small chip capable
of performing ALU operations and communicating with
the external devices connected to it.
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A Computer
A computer:
Accepts the data from the user.
Stores the data and the set of instructions supplied by
the user in memory.
Processes the data according to the instructions in the
processing unit.
Communicates the result to the user or stores it for
further reference.
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A Computer
A computer has the following units:
Input Unit
Output Unit
Memory Unit
Central Processing Unit
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A Computer
INPUT UNIT
The input unit consists of the devices which accept the data and
instructions from the user and communicates it to the CPU.
The various input devices are: keyboard, mouse, joystick, trackball
etc.
OUTPUT UNIT
It provides the result of the various operations performed by the
CPU to the user.
The various output devices are: printers, monitors, loudspeakers
etc.
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A Computer
CENTRAL PROCESSING UNIT (CPU)
The CPU is the heart and nerve centre of the computer.
It fetches the instruction and data from the peripheral
devices and performs all the arithmetic operations, takes
logical decision and control the operation of all other units. Various sub-blocks of the central processing unit are:
Arithmetic and Logic Unit (ALU)
Timing & Control Unit
Registers
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A Computer
ARITHMETIC AND LOGIC UNIT (ALU)
This unit perform all the logical and arithmetic operations. Various arithmetic operations are: addition, subtraction, increment and
decrement etc.
Various logical operations are: AND, OR, NOT, XOR, etc.
TIMING AND CONTROL UNIT
This unit controls the entire operations being performed by the system. It controls the operations of ALU, input/output devices and memory unit. This unit interprets the instructions and generates various timing and control
signals.
REGISTERS
A register is a very small amount of very fast memory that is built into the CPU
in order to store the current data and instructions which are being executed by the CPU.
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A Computer
MEMORY UNIT
It stores the program statement and the data i.e. the
information supplied from the input unit.
It also stores the final output.
This is connected to the CPU by means of a bidirectional
bus.
The CPU processes the information as taken from the
memory and performs the operations in the ALU section.
The results are either transferred to the output unit or stored
in the memory for later use by the CPU.
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A Micro-Computer
As the name implies, microcomputers are small
computers.
The block diagram of the microcomputer is similar to
the computer except that the central processing unit
of the microcomputer is contained in a single IC
called the microprocessor.
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A Micro-Computer
A microprocessor is a LSI (Large Scale Integration) IC
that does almost all the functions of the...
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