Evolution of Microprocessor – Types of Microprocessors

The microprocessor is nothing but the CPU and it is an essential component of the computer. It is a silicon chip that comprises millions of transistors and other electronic components that process millions of instructions per second. A Microprocessor is a versatile chip, that is combined with memory and special-purpose chips and preprogrammed by software. It accepts digital data as i/p and processes it according to the instructions stored in the memory. The microprocessor has many functions like functions of data storage, interact with various other devices, and other time-related functions. But, the main function is to send and receive the data to make the function of the computer well. This article discusses the types and evolution of microprocessor. Please follow this link for Microprocessor History and Generation of Microprocessor

Evolution of Microprocessor

The microprocessor has become a more essential part of many gadgets. The evolution of microprocessor was divided into five generations such as first, second, third, fourth, and fifth-generation and the characteristics of these generations are discussed below.


First Generation Microprocessors

The first generation microprocessors were introduced in the year 1971-1972. The instructions of these microprocessors were processed serially, they fetched the instruction, decoded and then executed it. When an instruction of the microprocessor was finished, then the microprocessor updates the instruction pointer & fetched the following instruction, performing this consecutive operation for each instruction in turn.

Second Generation Microprocessors

In the year 1970, a small number of transistors were available on the integrated circuit in the second-generation microprocessors. Examples of the second-generation microprocessors are 16-bit arithmetic 7 pipelined instruction processing, MC68000 Motorola microprocessor. These processors are introduced in the year 1979, and Intel 8080 processor is another example of the microprocessor. The second generation of the microprocessor is defined by overlapped fetch, decode, and execute the steps.  When the first generation is processed in the execution unit, then the second instruction is decoded and the third instruction is fetched.

The difference between the first generation microprocessor and second-generation microprocessors was mainly the use of new semiconductor technologies to manufacture the chips. The result of this technology resulted in a fivefold increase in instruction, speed, execution, and higher chip densities.

Third Generation Microprocessors

The third generation microprocessors were introduced in the year 1978, as denoted by Intel’s 8086 and the Zilog Z8000. These were 16-bit processors with a performance like mini computers. These types of microprocessors were different from the previous generations of microprocessors in that all main workstation industrialists began evolving their own ISC based microprocessor architectures.


Fourth Generation Microprocessors

As many industries converted from commercial microprocessors to in house designs, the fourth generation microprocessors are entered with outstanding design with a million transistors. Leading-edge microprocessors like Motorola’s 88100 and Intel’s 80960CA could issue & retire more than one instruction per clock cycle.

Fifth Generation Microprocessors

Fifth-generation microprocessors employed decoupled superscalar processing, and their design soon exceeded 10 million transistors. In the fifth generation, PCs are a low-margin, high volume business conquered by a single microprocessor.

On Dec 23rd, 1947, the Transistor was invented in Bell lab whereas an integrated circuit was invented in 1958 by J Kilby in Texas Instruments. So, Intel or INTegrated ELectronics has invented the first microprocessor.

Evolution of Microprocessor
Evolution of Microprocessor

4-bit Microprocessor

The INTEL 4004/4040 was invented in the year 1971 by Stanley Mazor & Ted Hoff. The clock speed of this microprocessor is 740 KHz. The number of transistors used in this microprocessor is 2,300 and instruction per second is 60K. The number of pins of this microprocessor is 16.

8-bit Microprocessor

  • The 8008 processor was invented in the year 1972. The clock speed of this microprocessor is 500 KHz and instruction per second is 50K
  • The 8080 microprocessor was invented in the year 1974. The clock speed is 2 MHz. The number of transistors used is 60k and instruction per second is 10 times quicker as compared with 8008 processor.
  • The 8085 microprocessor was invented in the year 1976. The clock speed is 3 MHz. The number of transistors used is 6,500 and instruction per second is 769230. The number of pins of this microprocessor is 40

16-bit Microprocessor

  • The 8086 microprocessor was invented in the year 1978. The clock speed is 4.77, 8 & 10 MHz. The number of transistors used is 29000 and instruction per second is 2.5 Million. The number of pins of this microprocessor is 40
  • The 8088 microprocessor was invented in the year 1979 and instruction per second is 2.5 Million
  • The microprocessors like 80186 or 80188 were invented in the year 1982. The clock speed is 6 MHz
  • The 80286 microprocessor was invented in the year 1982. The clock speed is 8 MHz. The number of transistors used is 134000 and instruction per second is 4 Million. The number of pins of this microprocessor is 68

32-bit Microprocessor

  • The Intel 80386 microprocessor was invented in the year 1986. The clock speed is 16 MHz to 33 MHz. The number of transistors used is 275000. The number of pins of this microprocessor is 132 14X14 PGA
  • The Intel 80486 microprocessor was invented in the year1986. The clock speed is 16MHz to 100 MHz. The number of transistors used is 1.2 Million transistors and instruction per second is 8 KB of cache memory. The number of pins of this microprocessor is 168 17X17 PGA (Pin Grid Array)
  • The PENTIUM microprocessor was invented in the year 1993. The clock speed is 66 MHz and instruction per second is Cache memory 8-bit for instructions 8- bit for data. The number of pins of this microprocessor is 237 PGA

64-bit Microprocessor

  • The INTEL core 2 microprocessor was invented in the year 2006. The clock speed is 1.2 GHz to 3 GHz. The number of transistors used is 291 Million and instruction per second is 64 KB of L1 cache for each core 4 MB of L2 cache.
  • The i3, i5, i7 microprocessors were invented in the years 2007, 2009, 2010 2. The clock speed is 2GHz to 3.3GHz, 2.4GHz to 3.6GHz & 2.93GHz to t 3.33GHz.

Evolution of Microprocessor in Different Applications

The following gadgets were implemented by using different microprocessors. So the evolution of microprocessor in different applications is discussed below.

Business Calculator

In the year 1971, a business calculator like Unicom 141P was invented. It was out of the leading gadgets that include a microprocessor.

Commodore PET

In the year 1971, this PET was implemented & is mostly recognized as the main all-in-one home computer.

Washing Machine

In 1977, the washing machines were launched which were controlled through leading microchips.

Arcade Mania

In the year 1980, the Arcade Maina was launched. Namco established Pac-Man within the pathway of the United States & ignited a novel trend.

Osborne 1 Laptop

In 1981, Osborne 1 Laptop was launched using five screens with 10.7kgs of weight. For most modern laptops, it is a great grand-father.

Nintendo NES

In 1986, the consoles refreshed the gaming business like Nintendo Entertainment System.

Computing Democratized

In the year 1991, the invention of Personal, as well as business computing, blasted through a wide variety of desktops laptops & tabs.

MP3 Player

In 1997, a music player was launched to enjoy music in a modern way


The Smartphone insurgence boosted with the launch of RIM’s Blackberry 850. The 1st BB was accessible in the year 1999.

Apple iPod

In the year 2001, the first iPod was launched which gave the prospect of MP3 music set-up a new range of set tunes.

Microsoft Windows Tablet

In the year 2002, Microsoft Windows Tablet was implemented, businesses were using these tabs for more helpful works.


In the year 2008, Netbooks were launched because of small as well as a light-weighted device for carrying out simple jobs, enjoying media & internet content.

Apple iPod

In 2010, Tabs hit the client’s main-stream through the release of the iPod.

Digital Signage

In the year 2011, Digital Signage was invented which was the first of the enormous new usages of the microprocessor. Academic, internet-connected devices were established in the everyday life from commerce & retail to farming as well as automobiles.


In the year 2011, Ultrabook was implemented. The development of the PC takes an extra gigantic step like fashionable Ultrabook devices with high-performance computing experience.

Types of Microprocessor

Microprocessors are classified into five types, namely: CISC-Complex Instruction Set Microprocessors, RISC-Reduced Instruction Set Microprocessor, ASIC- Application Specific Integrated Circuit, Superscalar Processors, DSP’s-Digital Signal Microprocessors.

Different Types of Microprocessor
Different Types of Microprocessor

Complex Instruction Set Microprocessors

The short term of Complex Instruction Set Microprocessors is CISM and they classify a microprocessor in which orders can be performed together along with other low-level activities. These types of processors perform different tasks like downloading, uploading, recalling data into the memory card, and recalling data from the memory card. Apart from these tasks, it also does complex mathematical calculations in a single command.

Reduced Instruction Set Microprocessor

The short term of Reduced Instruction Set Microprocessor is RISC. These types of processors are made according to the function in which the microprocessor can carry out small things in specific commands. In this way, these processors complete more commands at a faster rate.

Superscalar Microprocessors

Superscalar processor facsimiles the hardware on the processor to perform various tasks at a time. These processors can be used for ALUs or multipliers. They have different operational units and these processors can carry out more than one command by continuously transmitting several instructions to the extra operational units inside the processor.

The Application Specific Integrated Circuit

The short term of Application Specific Integrated Circuit processor is an ASIC. These processors are used for particular purposes that include automotive emissions control or personal digital assistant’s computer. This type of processor is made with the proper specification, but apart from these, it can also be made with off the shelf gears.

Digital Signal Multiprocessors

Digital signal processors are also called DSP’s, these processors are used to encode and decode the videos or to convert the D/A (digital to analog) &A/D (analog to digital). They need a microprocessor that is excellent in mathematical calculations. The chips of this processor are employed in RADAR, home theaters, SONAR, audio gears, TV set-top boxes, and Mobile phones

There are many companies like Intel, Motorola, DEC (Digital Equipment Corporation ), TI (Texas Instruments) associated with many microprocessors such as 8085 microprocessors, ASIC, CISM, RISC, DSPs and 8086 microprocessors like Intel


The main features of a microprocessor include the following.


Microprocessors are portable because of the size as well as less power consumption.

Low Cost

Microprocessors are available at less cost due to IC technology. So this technology will diminish the price of a computer system.


A microprocessor is versatile so it can be used for different applications


Microprocessors are reliable, so the rate of failure is less because of the semiconductor technology.

Small Size

The fabrication of microprocessors can be done in very less space because of the technologies used like VLSI & ULSI. So the computer system size will be reduced.

High Speed

Microprocessors perform very fast because of the technology used so it executes a number of instructions for each second.

Low Power Consumption

Microprocessors use low power because of the MOS technology

Low Heat Generation

Microprocessors cannot generate huge heat as compared with vacuum tube devices because it uses semiconductor technology.

Basic Terms

The basic terms mainly used in microprocessors are discussed below.

Instruction Set

The instruction set can be defined as the set of commands understood by the microprocessor. It is an edge between software as well as hardware.


The conductors which are used to transmit data, address otherwise control information for dissimilar elements within a microprocessor. It includes three types of buses namely data bus, control, and address bus


The IPC stands for Instructions per Cycle. It is a calculation of how many commands a CPU can execute within a single clock.

Clock Speed

When the no. of operations for each second can be performed by the processor is known as clock speed. The CLK speed can be expressed in MHz (megahertz) otherwise GHz (gigahertz). An alternate name for this is the Clock Rate.


The short term of the Bandwidth is BW and it can be defined as the no. of bits that can be processed within a single instruction.

Word Length

The word length is nothing but, when the no. of bits can be processed by the processor at a time. For instance, the 8-bit microprocessor is used to process 8-bit data at a time. The range of word length of a processor ranges from 4 – 64 bits based on the sort of the microcomputer.

Data Types

The microprocessor mainly supports several data type designs such as ASCII, binary, signed as well as unsigned numbers.

Advantages and Disadvantages of Microprocessors

The advantages of microprocessors are

  • The processing speed is high
  • Intelligence has been brought to systems
  • Flexible.
  • Compact size.
  • Easy maintenance
  • Complex mathematics

Some of the disadvantages of the microprocessor are it might get overheated and the limitation of the microprocessor imposes on the size of data.

The applications of the microprocessors mainly involve controllers in home appliances, wireless communication equipment, office publication and automation, consumer electronic goods, calculators, accounting system, video games, industrial controllers, and data acquisition systems

Thus, this is all about the types and evolution of microprocessor. The availability of a microprocessor with low power, low cost, small weight, and computing capability makes it useful in various applications. In the present day, microprocessor-based systems are used in the automatic testing product, traffic signal control systems, instructions,  speed control of motors, etc. Furthermore, any doubts regarding this evolution of microprocessor articles or electronic and electrical projects, please give your comments in the comment section box. Here is a question for you, which stack is used in the 8085 microprocessor?

Don’t Miss: Know about the difference between microprocessor and microcontroller.

Photo Credits:

  • Evolution of Microprocessor by bhs4


    1. Tarun Agarwal says:

      Hi Sai
      I sincerely appreciate your kind response regarding my article
      For more information on microprocessor, working applications and projects please refer to the link.
      For customization of projects please email us on team@elprocus.com

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