What is a Microprocessor : Generations and Its Types

The First Microprocessor like Intel 4004 was invented by Ted Hoff, Masatoshi Shima, Federico Faggin and Stanley Mazor. The size of these processors is 8bit processors (it read or write only 1 byte at a time), 16bit (it read or write only 2bytes at a time), 32bit (it read or write only 4 bytes at a time) and 64bit (it read or write the only byte at a time). It performs all the operations or functions depends on the program which is written in assembly language by the programmer and its lifetime is more than 3000 hours. Almost all household electronic products contain a microprocessor, some examples are washing machines, fridges, geysers, alarm systems, microwave oven, laptops, etc.

What is a Microprocessor?

The microprocessor is mostly used in embedded control applications such as household applications, automobiles, and computer peripherals. It is an integrated electronic circuit that controls all functions of the CPU, or central processing unit, of a computer or other digital devices. The entire function of the CPU is controlled by a single integrated circuit that accepts binary data as input and processes that data according to the given instructions then generates the output. This processor contains millions of tiny components like transistors, registers, and diodes. The block diagram of this processor is shown in the below figure.


Components of the Microprocessor

Components of this processor are ALU, Control unit, Input-output devices, and Register array.

  • ALU (arithmetic logic unit) performs both arithmetic and logical operations. Arithmetic operations such as addition, subtraction, multiplications, divisions, and logical operations such as NOR, AND, NAND, OR, XOR, NOT, XNOR, etc.
  •  The control unit is used to control the instructions and it generates the signals to operate the other components.
  •  The register array consists of registers. Registers that are used by the programmer to store arbitrary data are known as general-purpose registers and the registers which are not used by a programmer to store the data are known as the reserved registers. The length of the register is known as the word length of the computer.
  • Input-output devices are used to transfer data between microcomputers and external devices.

How Microprocessors are Made?

The microprocessors are made by silicon or germanium. Silicon and germanium are semiconductors, almost all electronic components are made by these semiconductors.

Generations of Microprocessor

There are five generations of this processor that mainly include the following.

  • First Generation Microprocessor: The first generation processors are 4 – bit microprocessor introduced in 1971 – 1972.
  • Second Generation Microprocessor: The second-generation processors are 8 – bit microprocessor introduced in 1973.
  • Third Generation Microprocessor: The third-generation processors are 16 – bit microprocessor introduced in 1978.
  • Fourth Generation Microprocessor: The fourth-generation processors are 32 – bit microprocessors.
  • Fifth Generation Microprocessor: The fifth-generation processors are 64 – bit microprocessor.

Working of Microprocessor

To get the output, the first microprocessor fetches the instructions from the computer memory and then decodes it and executes those instructions as a result in a binary form. The power of the given microprocessor is measured in terms of bits.


This processor executes the instruction using the following steps

  • Fetching (IF): It is the first step of the microprocessor which fetches the instruction from the memory.
  • Decoding (ID): It is the second step of the microprocessor used to decodes the instruction.
  • Executing (EX): It is the last step of this processor that executes the instructions and the output.

Types of Microprocessors

Types of processors are shown in the below figure.

  • Vector Processors: The vector processor is designed for vector computations and it is an array of operands. It is the process of using vectors to store a large number of variables for high-intensity data processing. Weather forecasting, human genome mapping, GIS data are some examples of vector processors are IBM 390/VF, DEC’S vax 9000, etc.
  • Processors or SIMD Processors: An array processor is also designed for vector computations and it is a single instruction multiple data (SIMD) processor. The applications of SIMD include image processing, 3d rendering, speech recognition, networking, DSP functions, etc.
  • Scalar and Superscalar Processors: The processor which executes scalar data is known as a scalar processor. Scalar processors are maybe the RISC scalar processor or CISC scalar processor. The superscalar processor executes more than one instruction per clock cycle and it has multiple pipelines.
  • Digital Signal Processors: Digital signal processors are used to process signals in a digital form. Applications of DSP are audio signal processing, digital image processing, video compression, audio compression, speech processing and recognition etc. Digital signal processors are Motorola 56000, national lm 32900 etc.
  • RISC Processors: The full form of RISC is reduced instruction set computer. The instructions in this processor are not complex. It is used in high-end applications such as video processing, telecommunications, and image processing.
  • CISC Processors: The full form of CISC is a complex instruction set computer. The instructions in this processor are complex. It requires an external memory for calculations. The CISC -architecture is used in low-end applications such as security systems, home automation, etc.
  • ASIC Processors: ASIC stands for application-specific integrated circuits. It is implemented for special functions or applications.

Best Companies of Microprocessor

 AMD (advanced micro devices), Intel, Nvidia, Marvell technology group, Enoceangmbh, Ensilica, ARM, Adaptevaare some best companies of this processor. AMD (advanced micro devices) company recently implemented AMD ryzen 9 3900x, AMD ryzen 5 2600x, etc and intel best microprocessor is Intel core i9-9900k.


The applications of this processor include the following.

  •  Gaming
  • Web browsing
  •  Creating documents
  •  Mathematical calculations
  •  Simulations
  • Photo editing
  •  In-home appliances
  •  In automotive electronics
  •  In metering
  •  In mobile electronics
  •  In building automation etc


The advantages of this processor include the following

  •  Low cost
  • High speed
  •  Small size
  •  Low power consumption
  •  Versatile
  •  Reliable
  •  Portable
  •  Easy to implement
  •  Easy to modify


The disadvantages of this processor include the following.

  •  Floating-point operations are not supported.
  • Sometimes it may get overheated.

Thus, this is all about an overview of the microprocessor. As we know that this processor is one of the best technology which can be used in almost all electronic products. Its usage is increasing day by day, compared to other technologies the cost is less and the speed of the microprocessor is high. Here is a question for you- what is the advance microprocessor using currently?