Microprocessor is an integrated circuit (IC) in the form of small chip present in the computer which is capable of interacting with devices connected to it. It consists of several components including Registers (to hold the data temporarily), Cache (to retain CPU last used data), Microcontrollers, Memory (RAM, ROM), ALU (Arithmetic Logic Operations; which carries the mathematical operations) etc. Invented in 1970’s, presently they are still used in most of the devices such as mobiles, cars, car keys, smoke alarms etc. It operates on binary logic and the input data is in binary, processes the input and the result comes out as output.
Microprocessor is the brain of Central Processing Unit (CPU). Microprocessor and Microcontroller are the components that have always confused people. There are some similarities and differences between them. Microprocessor also called CPU doesn’t have RAM, ROM etc. on the chip, it is installed externally. Microcontroller contains CPU, RAM, and ROM on single chip. Microprocessor performs unspecific tasks such as photo editing, websites etc. and in microcontroller input and output is fixed. Microprocessors are costlier and their complexing is much more whereas microcontrollers are cheap, simple and reliable.
Types of Microprocessors
- 8085 Microprocessor
Pronounced as eighty-eighty five processor was developed by Intel in 1977 using NMOS Technology. It has a 8 bit data bus and a memory capacity of 64 KB. 8085 processors has 6 general purpose registers namely, B, C, D, E, H and L. There are 5 flags Sign, Zero, Parity, Carry and Auxiliary Carry.
Data Memory- It uses 16 bit addresses to store data anywhere in the processor.
Stack Memory- It can be incremented or decremented during operations.
It has a 8 bit temporary register to store the operations temporarily. The processor has 5 interrupt signals- INTR, RST 7.5, RST 6.5, RST 5.5, TRAP.
- 8086 Microprocessor
It was designed by Intel in 1976 and is the updated and much better version of 8085 microprocessor. It has memory storage up to 1MB and is a 16 bit processor. It can also operate in Maximum and Minimum Modes . Logic 0 is for the maximum mode and Logic 1 is for the Minimum mode. To enhance the performance two types of pipelining is done: Fetch Stage and Execute Stage.
- RISC Processor
It stands for Reduced Instruction Set Computer and is designed to perform the computer instructions which a quite small and require less time for execution and the speed can be in seconds or MIPS. In one clock cycle the instruction can be completed and for that large RAM space is required.
- CISC Processor
It stands for Complex Instruction Set Computing and is designed to carry out low level operations with a single instruction. The advantage is that the number of instructions is reduced in it. CISC’s architecture is not complex and is capable for multiple operations with single instruction. Decoding of instructions is complex but the calculations are slow and precise.