Types of Microprocessor Classification:

In this tutorial we are going to learn about Types of Microprocessor Classification:

A microprocessor can be classified into three categories-

RISC Processor

It is  full form  is  reduced instruction set computer it is designed to reduce the execution time by simplifying the instruction set of the computer using RISC processors  each instruction requires only one clock cycle to execute results in uniform execution time this reduces results in uniform  execution time this reduces the efficiency as there are more lines of code while  maximum RAM is needed to store the instructions the compiler also has to work more to convert high-level language instructions into machine code

Some of the RISC processors are-

  • Power pc:  601, 604, 615,620
  • DEC alpha : 210642,211066,211066,21068,21164
  • MIIPS :TS (RI0000) RISC Processor
  • PA-RISC : HP 7100LC

Architecture of RISC

It is microprocessor architecture uses highly-optimized set of instructions it is used in portable devices like apple iPod due to its power efficiency.     

                              Characteristics of RISC

The major characteristic of a RISC processor are as follows-

  • It consist of simple instructions
  • It supports various data-type formats
  • It main purpose is simple addressing modes and fixed length instructions for pipelining
  • It support register to use in any context
  • One cycle execution time
  • It has instructions “LOAD” and “STORE” which are used to access the memory location
  • It consists of large number of registers

CISC Processor

It is full form is complex instruction set computer it is designed to minimize the number of instructions per program ignoring the number of cycles per instruction the emphasis is on building complex instructions directly into the hardware

The complier has to do very little work to translate a high-level language into assembly level language/machine code because the length of the code is relatively short so very little RM is required to store the instructions.

Some of the CISC processors are-

  • IBM 370/268
  • VAX 11/780
  • Intel 80486

Architecture of CISC

Cisc has maximum storage is needed in larger programs so that for  higher memory cost to resolve this the number of instructions per program can be reduce by embedding the number of operations in a single instruction due to this can decrease memory cost.

Characteristics of CISC

  • Variety of addressing modes
  • Larger number of instructions
  • For execute one instruction required several cycles
  • For Instruction need  to support multiple addressing modes


It is basically use of microprocessor which can handle its particular function many times faster than the ordinary microprocessor

For example- math coprocessor

Some intel math – coprocessor are-

  • 8087-used with 8026
  • 80287-used with 80286
  • 80387-used with 80386

Input/output processor

It is basically use of microprocessor which having a local memory of its own, which is used to control I/O devices with minimum CPU involvement

For example-

  • DMA (direct memory access) controller
  • Keyboard /mouse controller
  • Graphic display controller
  • SCSI port controller

Transputer (Transistor Computer)

Transputer has own links which is use connect one transputer to another tansputer communications & it has own local memory,  it was first designed in 1980 by Inmos and is targeted to the development in  Very large scale technology Integrated  & also used as a single processor system or can be connected to external links which reduces the construction cost and increase the performance, Like that 16-bit for T212 , 32 bit for T425 the floating point (T800 , T 805 & T9000) processors

DSP (digital signal processor)

It is specially designed  to process the analog signals into a digital form this is done by sampling the voltage level at regular time intervals and converting  the voltage at this instant  into a digital form this process is performed by a circuit called an analogue to digital converter A to D converter or ADC

A DSP contains the following components-

  • Program memory- it store the programs that DSP will use to process data
  • Data memory- It is main use to stores the information to be processed
  • Compute engine-Compute Engine which  performs the mathematical processing accessing the program from the program memory and the data from the data memory
  • Input/output-it connects to the outside world

Its applications are-

  • Sound and music synthesis
  • Audio and video compression
  • 2D and 3d graphics acceleration

For example – Taxes Instrument’s TMS320 series e.g.TMS320c40 TMS320C50

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