This document discusses machine instructions and program execution. It describes the objectives as explaining machine instructions and program execution, number representation and arithmetic, addressing methods, assembly language, and input/output operations. It then defines three types of machine instructions and the four main steps of machine instruction execution: fetch, decode, execute, and store. Finally, it explains that machine instructions make up machine language programs and allow computers to directly execute commands through their central processing units.

1. BUDGE BUDGE INSTITUTE
OF TECHNOLOGY
DEPARTMENT OF ELECTRONICS AND COMMUNICATION
ENGINEERING
SUBJECT-COMPUTER ARCHITECTURE
NAME-ANKITA DEY
REG NO-27600322034
YEAR-3rd
SEM-5th
YEAR-2023-2024
PROJECT PRESENTATION ON
“Machine instruction and programes”.

2. OBJECTIVES
• Machine instructions and program execution, including branching and
subroutine call and return operations.
• Number representation and addition/subtraction in the 2’s-complement
system.
• Addressing methods for accessing register and memory operands.
• Assembly language for representing machine instructions, data, and
programs.
• Program-controlled Input/Output operations.

3. TYPES OF MACHINE INSTRUCTIONS
• Data Transfer instructions.
• Data Manipulation Instructions (Computation) : Arithmetic
and Logical Instructions.
• Program Control Instructions.

4. MACHINE INSTRUCTIONS – FOUR MAIN STEPS
• Fetch: the processor fetches the instruction from the memory address. It stores the address
in the PC (Program Counter) and IR (Instruction Register). The PC points to the next instruction
at the end of the fetch operation.
• Decode: the processor interprets and decodes the instruction. The instruction within the IR gets
decoded.
• Execute: the CPU’s Control Unit decodes the data as a sequence of control signals to the
CPU’s relevant function units. These units perform the actions that the instruction ‘instructs.’
• Store: the operation generates a result, which the processor stores in the main memory.
Sometimes, it may send it to an output device.

6. MACHINE INSTRUCTIONS MAKE UP THE
MACHINE LANGUAGE PROGRAM
• Machine instructions are machine code programs or commands. In other words,
commands written in the machine code of a computer that it can recognize and
subsequently execute.
• Machine code or machine language refers to a computer programming language
consisting of a string of ones and zeros, i.e., binary code. Computers can respond to
machine code directly, i.e., without any direction or conversion.
• One machine instruction consists of several bytes of memory. It tells the computer’s CPU to
perform one machine operation. CPU stands for Central Processing Unit.

7. CONCLUSION
Human programmers do not write programs as long strings of ones and
zeros or sequences of binary digits. They use Python, BASIX, Ruby,
Java, C++, or another programming language. We call these high-
level programming languages.