Microprocessor Basics

The processor on a single chip is called a Microprocessor which can process micro-instructions. Instructions in the form of 0s and 1s are called micro-instructions. The microprocessor is the CPU part of a microcomputer, and it is also available as a single integrated circuit. Thus as main components, the microprocessor will have the Control Unit (CU) and the Arithmetic Logic Unit (ALU) of a microcomputer. An example is Intel 8085 microprocessor. In addition to the microprocessor features, a microcomputer will have the following additional features −

  • ROM / PROM / EPROM / EEPROM for storing program

  • RAM for storing data, intermediate results, and final results

  • I/O devices for communication with the outside world

  • I/O ports for communication with the I/O devices.

In the present-day world, Microprocessors are extensively used. Before the microprocessor’s invention, the logic design was done by hardware using gates, flip-flops, etc. A mini-computer was too much costly. With the advent of the microprocessor, logic design using hardware has been mostly replaced. It provides flexibility instrumentation where the characteristics of the system can be changed just by changing the software. Also, new generations of applications have surfaced, which were not thought of earlier because of the prohibitive cost of a minicomputer or the complexity of logic design using hardware.

Some of the applications where microprocessors have been used are listed below –

  • Business applications such as desktop publishing

  • Industrial applications such as power plant control

  • Measuring instruments such as multimeter

  • Household equipment such as washing machine

  • Medical equipment such as blood pressure monitor

  • Defense equipment such as light combat aircraft

  • Computers such as a personal computer.

How does a Microprocessor Work?

The microprocessor follows a sequence: Fetch, Decode, and then Execute.

Initially, the instructions are stored in the memory in sequential order. The microprocessor fetches those instructions from the memory, then decodes it and executes those instructions till STOP instruction is reached. Later, it sends the result in binary to the output port. Between these processes, the register stores the temporary data andALU performs the computing functions.

List of Terms Used in a Microprocessor

Here is a list of some of the frequently used terms in a microprocessor −

  • Instruction Set − It is the set of instructions that the microprocessor can understand.

  • Bandwidth − It is the number of bits processed in a single instruction.

  • Clock speed − It determines the number of operations per second the processor can perform. It is expressed in megahertz (MHz) or gigahertz (GHz). It is also known as Clock Rate.

  • Word Length − It depends upon the width of the internal data bus, registers, ALU, etc. An 8-bit microprocessor can process 8-bit data at a time. The word length ranges from 4 bits to 64 bits depending upon the type of the microcomputer.

  • Data Types − The microprocessor has multiple data type formats like binary, BCD, ASCII, signed and unsigned numbers.

Features of a Microprocessor

Here is a list of some of the most prominent features of any microprocessor −

  • Cost-effective −The microprocessor chips are available at low prices and results in its low cost.

  • Size −The microprocessor is of small size chip, hence is portable.

  • Low Power Consumption −Microprocessors are manufactured by using metal oxide semiconductor technology, which has low power consumption.

  • Versatility −The microprocessors are versatile as we can use the same chip in a number of applications by configuring the software program.

  • Reliability −The failure rate of an IC in microprocessors is very low, hence it is reliable.