KTU - CST202 - Computer Organization and Architecture Module: 1
BASIC STRUCTURE OF COMPUTERS - Functional units – Basic operational
concepts – Bus structures. Memory locations and addresses – memory
operations – instructions and instruction sequencing – addressing modes.
Module: 1 Basic processing unit -Fundamental concepts –instruction cycle -
execution of a complete instruction –single bus and multiple bus
organization.
WHY COMPUTER ORGANIZATION AND ARCHITECTURE?
Computer architecture is a key component of computer engineering and it is concerned
with all aspects of the design and organization of the central processing unit and the integration
of the CPU into the computer system itself.
Architecture extends upward into computer software because a processor’s architecture
must cooperate with the operating system and system software. It is difficult to design an
operating system well without knowledge of the underlying architecture.
Moreover, the computer designer must have an understanding of software in order to
implement the optimum architecture.
INTRODUCTION
Computer: A device that accepts input, processes data, stores data, and produces output, all
according to a series of stored instructions.
Software: A computer program that tells the computer how to perform particular tasks.
Hardware: Includes the electronic and mechanical devices that process the data; refers to the
computer as well as peripheral devices.
Peripheral devices: Used to expand the computer’s input, output and storage capabilities.
Network: Two or more computers and other devices that are connected, for the purpose of
sharing data and programs.
Computer Types:Computers are classified based on the parameters likeSpeed of operation, Cost,
Computational power and Type of application
Difference between computer organization and computer architecture
Architecture describes what the computer does and organization describes how it does it.
Computer organization:
Computer organization is concerned with the way the hardware components operate and
the way they are connected together to form computer system. It includes Hardware details
1
,KTU - CST202 - Computer Organization and Architecture Module: 1
transparent to the programmer such as control signal and peripheral. It describes how the
computer performs. Example: circuit design, control signals, memory types this all are under
computer organization.
Computer Architecture:
Computer architecture is concerned with the structure and behavior of computer system
as seen by the user. It includes information, formats, instruction set and techniques for
addressing memory. It describes what the computer does.
FUNCTIONAL UNITS:
The computer system is divided into five separate units for its operation.
Input Unit.
ALU.
Control Unit.
Memory Unit.
Output Unit.
Input & Output unit
The method of feeding data and
programs to a computer is accomplished
by an input device. Computer input Figure 1
devices read data from a source, such as
magnetic disks, and translate that data into electronic impulses [ADC] for transfer into the CPU.
Some typical input devices are a keyboard, a mouse, scanner, etc.
Computer output devices converts the electronic impulses [DAC] into human readable
form. Output unit sends processed results to the outside world. Examples: Display screens,
Printers, plotters, microfilms, synthesizers, high-tech blackboards, film recorders, etc.
Memory Unit (MU)
A Memory Unit is a collection of storage cells together with associated circuits needed to
transfer information in and out of storage. Data storage is a common term for archiving data or
information in a storage medium for use by a computer. It’s one of the basic yet fundamental
functions performed by a computer. It’s like a hierarchy of comprehensive storage solution for
fast access to computer resources.
A computer stores data or information using several methods, which leads to different
levels of data storage. Primary storage is the most common form of data storage which typically
refers to the random access memory (RAM). It refers to the main storage of the computer
because it holds data and applications that are currently in use by the computer. Then, there is
2
, KTU - CST202 - Computer Organization and Architecture Module: 1
secondary storage which refers to the external storage devices and other external media such as
hard drive and optical media.
Arithmetic Logical Unit (ALU)
After you enter data through the input device it is stored in the primary storage unit.
Arithmetic Logical Unit performs the actual processing of data and instruction. The major
operations performed by the ALU are addition, subtraction, multiplication, division, logic and
comparison.
Data is transferred to ALU from storage unit when required. After processing, the output
is returned back to storage unit for further processing or getting stored.
Control Unit
The next component of computer is the control unit, which acts like the supervisor seeing
whether things are done in proper fashion. Control unit controls and coordinates the entire
operations of the computer system.
The control unit determines the sequence in which computer programs and instructions
are executed. Things like processing of programs stored in the main memory, interpretation of
the instructions and issuing of signals for other units of the computer to execute them.
It also acts as a switch board operator when several users access the computer
simultaneously. Thereby it coordinates the activities of computer’s peripheral equipment as they
perform the input and output. Therefore it is the manager of all operations.
Central Processing Unit (CPU)
The Arithmetic Logical Unit (ALU), Control Unit (CU) and Memory Unit (MU) of a
computer system are jointly known as the central processing unit. We may call CPU as the brain
of any computer system. It is just like a human brain that takes all major decisions, makes all
sorts of calculations and directs different part of the computer by activating and controlling the
operations.
BASIC OPERATIONAL CONCEPTS
To perform a given task, an appropriate program consisting of a list of instructions is
stored in the memory. Individual instructions are brought from the memory into the processor,
which executes the specified operations. [Load – Transfers data to register. Store – Transfers
data to memory.] A typical instruction might be
The operand at LOC is fetched from the memory into the processor. The
Load LOC,R2 operand is stored in register R2.
Adds the contents of registers R1 and R2, then places their sum into
Add R1, R2, R3 register R3.
Store R4, LOC This instruction copies the operand in register R4 to memory location
Add R1, R0 Add contents of R1, R0 and place the sum to R0.
3
BASIC STRUCTURE OF COMPUTERS - Functional units – Basic operational
concepts – Bus structures. Memory locations and addresses – memory
operations – instructions and instruction sequencing – addressing modes.
Module: 1 Basic processing unit -Fundamental concepts –instruction cycle -
execution of a complete instruction –single bus and multiple bus
organization.
WHY COMPUTER ORGANIZATION AND ARCHITECTURE?
Computer architecture is a key component of computer engineering and it is concerned
with all aspects of the design and organization of the central processing unit and the integration
of the CPU into the computer system itself.
Architecture extends upward into computer software because a processor’s architecture
must cooperate with the operating system and system software. It is difficult to design an
operating system well without knowledge of the underlying architecture.
Moreover, the computer designer must have an understanding of software in order to
implement the optimum architecture.
INTRODUCTION
Computer: A device that accepts input, processes data, stores data, and produces output, all
according to a series of stored instructions.
Software: A computer program that tells the computer how to perform particular tasks.
Hardware: Includes the electronic and mechanical devices that process the data; refers to the
computer as well as peripheral devices.
Peripheral devices: Used to expand the computer’s input, output and storage capabilities.
Network: Two or more computers and other devices that are connected, for the purpose of
sharing data and programs.
Computer Types:Computers are classified based on the parameters likeSpeed of operation, Cost,
Computational power and Type of application
Difference between computer organization and computer architecture
Architecture describes what the computer does and organization describes how it does it.
Computer organization:
Computer organization is concerned with the way the hardware components operate and
the way they are connected together to form computer system. It includes Hardware details
1
,KTU - CST202 - Computer Organization and Architecture Module: 1
transparent to the programmer such as control signal and peripheral. It describes how the
computer performs. Example: circuit design, control signals, memory types this all are under
computer organization.
Computer Architecture:
Computer architecture is concerned with the structure and behavior of computer system
as seen by the user. It includes information, formats, instruction set and techniques for
addressing memory. It describes what the computer does.
FUNCTIONAL UNITS:
The computer system is divided into five separate units for its operation.
Input Unit.
ALU.
Control Unit.
Memory Unit.
Output Unit.
Input & Output unit
The method of feeding data and
programs to a computer is accomplished
by an input device. Computer input Figure 1
devices read data from a source, such as
magnetic disks, and translate that data into electronic impulses [ADC] for transfer into the CPU.
Some typical input devices are a keyboard, a mouse, scanner, etc.
Computer output devices converts the electronic impulses [DAC] into human readable
form. Output unit sends processed results to the outside world. Examples: Display screens,
Printers, plotters, microfilms, synthesizers, high-tech blackboards, film recorders, etc.
Memory Unit (MU)
A Memory Unit is a collection of storage cells together with associated circuits needed to
transfer information in and out of storage. Data storage is a common term for archiving data or
information in a storage medium for use by a computer. It’s one of the basic yet fundamental
functions performed by a computer. It’s like a hierarchy of comprehensive storage solution for
fast access to computer resources.
A computer stores data or information using several methods, which leads to different
levels of data storage. Primary storage is the most common form of data storage which typically
refers to the random access memory (RAM). It refers to the main storage of the computer
because it holds data and applications that are currently in use by the computer. Then, there is
2
, KTU - CST202 - Computer Organization and Architecture Module: 1
secondary storage which refers to the external storage devices and other external media such as
hard drive and optical media.
Arithmetic Logical Unit (ALU)
After you enter data through the input device it is stored in the primary storage unit.
Arithmetic Logical Unit performs the actual processing of data and instruction. The major
operations performed by the ALU are addition, subtraction, multiplication, division, logic and
comparison.
Data is transferred to ALU from storage unit when required. After processing, the output
is returned back to storage unit for further processing or getting stored.
Control Unit
The next component of computer is the control unit, which acts like the supervisor seeing
whether things are done in proper fashion. Control unit controls and coordinates the entire
operations of the computer system.
The control unit determines the sequence in which computer programs and instructions
are executed. Things like processing of programs stored in the main memory, interpretation of
the instructions and issuing of signals for other units of the computer to execute them.
It also acts as a switch board operator when several users access the computer
simultaneously. Thereby it coordinates the activities of computer’s peripheral equipment as they
perform the input and output. Therefore it is the manager of all operations.
Central Processing Unit (CPU)
The Arithmetic Logical Unit (ALU), Control Unit (CU) and Memory Unit (MU) of a
computer system are jointly known as the central processing unit. We may call CPU as the brain
of any computer system. It is just like a human brain that takes all major decisions, makes all
sorts of calculations and directs different part of the computer by activating and controlling the
operations.
BASIC OPERATIONAL CONCEPTS
To perform a given task, an appropriate program consisting of a list of instructions is
stored in the memory. Individual instructions are brought from the memory into the processor,
which executes the specified operations. [Load – Transfers data to register. Store – Transfers
data to memory.] A typical instruction might be
The operand at LOC is fetched from the memory into the processor. The
Load LOC,R2 operand is stored in register R2.
Adds the contents of registers R1 and R2, then places their sum into
Add R1, R2, R3 register R3.
Store R4, LOC This instruction copies the operand in register R4 to memory location
Add R1, R0 Add contents of R1, R0 and place the sum to R0.
3
