CENTRAL PROCESSING UNIT(CPU)
CPU is also known as a processor or microporcessor.CPU is the brain of a computer system.Inside a CPU there are thousands of microscopic transistors,which are tiny switches that control the flow of electricity through the integrated circuits.A CPU is responsible for handling the processing of logical and mathematical operations and executing intructions that it is given.
The main parts of a CPU
- and Registers.
CPU has the four main task:-
A control unit handles all processor control signals.It directs all input and output flow,fetches code for instructions from microprograms and directs other units and models by providing control and timing signals.A CU component is considered the processor brain because it issues orders to just about everything and ensures correct instruction execution.
CUs are designed in two way
- Hardwired control
- Microprograme control
CU functions are as follows:-
- Controls sequential instructions execution,
- Interprets instructions,
- Guides data flow through different computer areas,
- Regulates and controls processor timing,
- Sends and receives control signals from other computer devices,
- Handles multiple tasks.
Arithmetic Logic Unit(ALU):-
An arithmetic logic unit is a major component of the central processing unit of a computer system.In some microprocessor architectures,the ALU is divided into the arithmetic unit(AU) and the logic unit(LU).An arithmetic logic unit is also known as an integer unit(IU).The main functions of the ALU are to do arithmetic,logic operations and bit shifting operations.
Main memory is the primary,internal workspace in the computer.
Storage Evaluation Criteria:-
- Storage capacity,
- Access time,
- Cost per bit of storage,
- Random access.
Main memory capacity of a computer is defined as number of bytes that can be stored in its main memory.
Types of memory:-
Random Access Memory(RAM):-
RAM is volatile and writable, RAM chips are of two types-dynamic and static.
Read Only Memory(ROM)
ROM is non-volatile and read-only.ROM are also known as field stores,permanent stores or dead stores.ROM are of two types-manufacturer programmed and user programmed.
Programmable Read Only Memory(PROM)
PROM is non-volatile storage information stored in it remains intact even in case of power off or interruption of power.
Erasable Programmable Read Only Memory(EPROM):-EPROM chips are of two types:-Ultra Violet EPROM(UVEPROM) and Electrically EPROM(EEPROM) also known as flash memory.
Cache is the temporary memory officially termed"CPU cache memory".It improves the efficiency of data retrieval.