microprocessor definition

What is microprocessor?

A microprocessor is an electronic device which is interfaced with memories and several other input and output devices. Thus, a study of microprocessors implies a study of a variety of memory chips, input/output devices, and techniques for interfacing them to the microprocessor.

Like any other digital computer, a system designed around a microprocessor needs to be programmed. Thus, a sequence of instructions needs to be formulated and input to the microprocessor-based system for effective operation. A sequence of instructions designed to perform a particular task is known as a program. A set of programs written for a microprocessor based system is known as the software for that system. Both hardware and software design are of paramount importance in microprocessor-based system design.

Microprocessor is just like any other electronic chip. It is more powerful than just any other chip. A µp is a device that:

· Has a limited set of on-chip memory locations, known as registers,, to hold information,

· Can understand a fixed set off basic commands, and

· Can generate signals to control external devices.

Inside the chip, there is an arithmetic logic unit (ALU). The ALU executes all arithmetic and logic instructions. For example, the arithmetic addition and logical AND operations will be performed by the ALU.

The registers inside the µp hold data on which the operations are performed. The control unit generates the external control signals and also controls the operation of the internal on-chip circuitry. The on-chip memory, in the form of registers, is generally very limited. Thus, almost every µp based system has an off-chip memory also.

The set of basic commands that a µp can understand, is known as the instruction set of the µp.

A µp does not have enough memory for program and data storage, neither does it has any input and output devices. Thus, when a µp is used to design a system, several other chips are also used to make up a complete system.

The first microprocessor was introduced in 1971 by Intel Corporation.