1. COMPUTER ORGANIZATION & ASSEMBLY LANGUAGE
INTRODUCTION
Introduction
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2. INTRODUCTION
Computer is an electronic machine, which solves problem → deals with electrical signals
Digital → information is presented by variables takes a limited number of discrete values.
Discrete values are processed internally by components that contain a limited number of discrete states.
Introduction
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3. INTRODUCTION Ex. Decimal digits: 0, 1, 2,…..9 → 10 discrete values.
Binary number: 0, 1.
Computers use binary system because:
It is easy to tell if electrical devices are on (1) or off (0).
Electrical and magnitude storage devices having 2 stable states are simple to construct.
Digital circuits are less affected by noise.
Introduction
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4. INTRODUCTION
A binary digit is called a bit → information is represented in digital computer in groups of bits.
Computer
Hardware Software
Introduction
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5. INTRODUCTION
Hardware: All electronic components and electromechanical devices that comprise the physical entity of device.
Software: Instructions and data that the computer manipulates to perform various tasks.
Program: A sequence of instructions for the computer.
Introduction
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6. BLOCK DIAGRAM OF COMPUTER
CPU:
ALU, CCU & registers
Output units
Input units
Memory
Introduction
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7. Central Processing Unit (CPU)
Brain of the computer
Consists of ALU ( Arithmetic and Logic Unit ): responsible for performing Arithmetic and Logical Operations.
Consists of CU ( Control Unit ) : tells the ALU what to do.
Consists of Registers : Internal memory of CPU to store temporary data.
Also referred as Microprocessor
Introduction
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8. MEMORY UNIT Memory devices are to store the data for later reference.
Broadly classified into two :
Primary Memory ( Main Memory )
Secondary Memory
Introduction
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9. INPUT UNIT Accepts data from the outside world
Converts data into the computer understandable form i.e. Binary form
Example of Input devices: Keyboard, Mouse, Microphone, etc.
Introduction
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10. OUTPUT UNIT Produces the output in user readable form.
Example of input devices: Monitor, Printer, Speakers, Plotter
Introduction
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11. Architecture & Organization
Architecture is those attributes visible to the programmer
Instruction set, number of bits used for data representation, I/O mechanisms, addressing techniques.
e.g. Is there a multiply instruction?
Organization is how features are implemented
Control signals, interfaces, memory technology.
e.g. Is there a hardware multiply unit or is it done by repeated addition?
Introduction
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12. Architecture & Organization
All Intel x86 family share the same basic architecture
The IBM System/370 family share the same basic architecture
This gives code compatibility
At least backwards
Organization differs between different versions
Introduction
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13. Programming languages
Machine language ML = binary
Difficult to use by programmer
Invented new notations that were closer to the way humans think→ program to translate from symbolic notations to binary = assembler
Symbolic language = assembly language ASM
Introduction
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14. Programming languages
Assembly language → write one line for every instruction that the machine will follow (programmer must think like machine) →
program that translates from higher level notations closer to natural languages (high-level language) to assembly language
High-level language HLL
Introduction
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15. Programming languages
Machine language: The language a particular processor understands
Assembly language: machine-specific language with a one-to-one correspondence with the machine language for that computer
Introduction
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16. Software layers Machine language Assembly language High-level language
Assembly language
MOV AX, 3CH
ADD AX, 20H
High-level language
y = 15;
y = y+32;
Introduction
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17. Advantages of HLL
It is easier to convert a natural language algorithm to a HLL program.
It is easier to read & understand HLL program than ASM program.
ASM generally contains more statements than equivalent HLL program → more time is required to code the ASM program.
Introduction
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18. Advantages of HLL
Each computer has its own ASM → ASM programs are limited to one machine, but HLL program can be executed on any machine that has a compiler for that language.
Introduction
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19. Advantages of ASM language
Efficiency:
A well-written assembly language program produces a faster, shorter machine language program.
Some operations, such as reading or writing to specific memory locations & I/O ports, can be done easily in ASM but may be impossible at a higher level.
Introduction
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20. Advantages of ASM language
Studying ASM → gain a feeling for the way the computer thinks and the way that things happen inside the computer.
Introduction
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