The central processing unit
in this we are providing the details of the central processing unit. This will be useful for the upcoming TRB computer instructor exam.
The central processing unit:
- The part of a computer in which operations are controlled and executed.
- The central processing unit(CPU) is the unitwhich performs most of the processing inside a computer. To control instructions and data flow to and from other parts of the computer, the CPU relies heavily on a chipset, which is a group of microchips located on the motherboard
ALU(arithmetic and logic unit):
- Arithmetic logic unit: Computer arithmetic is a branch of computer engineering that deals with methods of representing integers and real values (e.g., fixed- and floating-point numbers) in digital systems and efficient algorithms for manipulating such numbers by means of hardware circuits or software routines.
- This refers to bit addition and subtraction. Although multiplication and division are sometimes used, these operations are more expensive to make. Multiplication and subtraction can also be done by repetitive additions and subtractions respectively.
- Different operation as carried out by ALU can be categorized as follows :
- logical operations: These include operations like AND, OR, NOT, XOR, NOR, NAND, etc.
- Bit-Shifting Operations: This pertains to shifting the positions of the bits by a certain number of places either towards the right or left, which is considered a multiplication or division operations.
Floating Point Arithmetic
- Floating Point Arithmetic: Issues and Limitations.Floating–point numbers are represented in computer hardware as base 2 (binary) fractions. For example, the decimal fraction. 0.125. has value 1/10 + 2/100 + 5/1000, and in the same way the binary fraction.
- example: 0.123 floating point.
The central processing unit
The central processing unit:
- The part of a computer in which operations are controlled and executed.
- The central processing unit(CPU) is the unitwhich performs most of the processing inside a computer. To control instructions and data flow to and from other parts of the computer, the CPU relies heavily on a chipset, which is a group of microchips located on the motherboard
ALU(arithmetic and logic unit):
- Arithmetic logic unit: Computer arithmetic is a branch of computer engineering that deals with methods of representing integers and real values (e.g., fixed- and floating-point numbers) in digital systems and efficient algorithms for manipulating such numbers by means of hardware circuits or software routines.
- This refers to bit addition and subtraction. Although multiplication and division are sometimes used, these operations are more expensive to make. Multiplication and subtraction can also be done by repetitive additions and subtractions respectively.
- Different operation as carried out by ALU can be categorized as follows :
- logical operations: These include operations like AND, OR, NOT, XOR, NOR, NAND, etc.
- Bit-Shifting Operations: This pertains to shifting the positions of the bits by a certain number of places either towards the right or left, which is considered a multiplication or division operations.
Floating Point Arithmetic
- Floating Point Arithmetic: Issues and Limitations.Floating–point numbers are represented in computer hardware as base 2 (binary) fractions. For example, the decimal fraction. 0.125. has value 1/10 + 2/100 + 5/1000, and in the same way the binary fraction.
- example: 0.123 floating point.
Insrtuction Set
Instruction set:
The instruction set, also called ISA (instruction set architecture), is part of a computer that pertains to programming, which is basically machine language. It provides commands to the processor, to tell it what it needs to do. The instruction set consists of addressing modes, instructions, native data types, registers, memory architecture, interrupt, and exception handling, and external I/O.
- Examples of instruction set
- ADD– Add two numbers together.
- COMPARE– Compare numbers.
- IN– Input information from a device, e.g., keyboard.
Types of operands:
There are four different types of operands that can appear in an instruction: – Directoperand – an operand stored in the register or in the memory location specified. – Indirect operand – an operand whose address is stored in the register or in the memory location specified.
- An operator is the ‘function’ that performs the operation, whereas the operand is the input to that function. In the expression 3 + 4 = 7, the operator is ‘+’ – since it’s telling us how to perform the operation – and the operands are 3 and 4 – the inputs upon which the operation is acting.
Example : 5+3=8, 5,3,8 operands
“+” is a operator.
Three Basic Types of Operands:
Immediate:
- Constant integer (8, 16, or 32 bits)
- Constant value is stored within the instruction
Register:
- Name of a register is specified
- Register number is encoded within the instruction
Memory:
- Reference to a location in memory
- Memory address is encoded within the instruction, or Register holds the address of a memory location.
Examples of operations common to many instruction sets include:
- Data handling and memory operations.
- Arithmetic and logic operations.
- Control flow operations.
- Coprocessor instructions.
- Number of operands.
Instruction set register organization
- On traditional architectures, an instruction includes an opcode that specifies the operation to perform, such as add contents of memory to register—and zero or more operand specifiers, which may specify registers, memory locations, or literal data.
- A program residing in the memory unit of a computer consists of a sequence of instructions. These instructions are executed by the processor by going through a cycle for each instruction.
- In a basic computer, each instruction cycle consists of the following phases:
- Fetch instruction from memory.
- Decode the instruction.
- Read the effective address from memory.
- Execute the instruction.
Instruction Set
Instruction set:
The instruction set, also called ISA (instruction set architecture), is part of a computer that pertains to programming, which is basically machine language. It provides commands to the processor, to tell it what it needs to do. The instruction set consists of addressing modes, instructions, native data types, registers, memory architecture, interrupt, and exception handling, and external I/O.
- Examples of instruction set
- ADD– Add two numbers together.
- COMPARE– Compare numbers.
- IN– Input information from a device, e.g., keyboard.
Types of operands:
There are four different types of operands that can appear in an instruction: – Directoperand – an operand stored in the register or in the memory location specified. – Indirect operand – an operand whose address is stored in the register or in the memory location specified.
- An operator is the ‘function’ that performs the operation, whereas the operand is the input to that function. In the expression 3 + 4 = 7, the operator is ‘+’ – since it’s telling us how to perform the operation – and the operands are 3 and 4 – the inputs upon which the operation is acting.
Example : 5+3=8, 5,3,8 operands
“+” is a operator.
Three Basic Types of Operands:
Immediate:
- Constant integer (8, 16, or 32 bits)
- Constant value is stored within the instruction
Register:
- Name of a register is specified
- Register number is encoded within the instruction
Memory:
- Reference to a location in memory
- Memory address is encoded within the instruction, or Register holds the address of a memory location.
Examples of operations common to many instruction sets include:
- Data handling and memory operations.
- Arithmetic and logic operations.
- Control flow operations.
- Coprocessor instructions.
- Number of operands.
Instruction set register organization
- On traditional architectures, an instruction includes an opcode that specifies the operation to perform, such as add contents of memory to register—and zero or more operand specifiers, which may specify registers, memory locations, or literal data.
- A program residing in the memory unit of a computer consists of a sequence of instructions. These instructions are executed by the processor by going through a cycle for each instruction.
- In a basic computer, each instruction cycle consists of the following phases:
- Fetch instruction from memory.
- Decode the instruction.
- Read the effective address from memory.
- Execute the instruction.
Read also
The Computer System-Computer Memory Overview
TRB Syllabus, Exam Pattern, Previous Year Questions, Study Books, Notes, Study Materials.