Microprocessor Explained in Easy Terms

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Micro-computer has a controlling unit which is fabricated on the small chip which can perform all the operations of the arithmetic logic unit is called the microprocessor. The other main function of the term is to communicate with the devices which are in its connection.

The main components of a microprocessor are the register array, ALU, and a control unit. Every element of the list of the components has its separate operations to perform. For instance,

  • Performing the arithmetic as well as logic operations on the received data is the work of the ALU. It presents the function from an input device or the memory.
  • In the register array, there are registers which are identified as well as divided by their unique name. Let’s say, B, C, D, E, H, L, and accumulator. These all are the registers of the array which make the functioning easy for the computer system.
  • The function of the control unit is specified with its name only. It manages and controls the data, as well as instructions, flows within the computer.

Let us have a look at the working of the microprocessor


There is a sequence in which the microprocessor of the computer functions. It follows the sequence, fetches, decodes and execute.

It begins by storing the instructions in the memory and that too in the sequential order. It is the microprocessor which fetches the data and the instructions from the available memory. After this, it decodes the data and then it has to execute the instructions till the time the processor reaches the STOP instructions. After doing all the instructions, it is the time to send the results of the fetched data in the form of binary to the output port. The registers also come into the picture when it temporarily stores the data. Then the arithmetic and logic unit is responsible for the computation of the functions.

There are various terms to be used in the concept of the microprocessor. We will discuss some frequently used terms one by one in brief.

  1. Word Length- The word length of the microprocessor is always depended on the registers, ALU, internal data bus, and many more. The microprocessor processes the data according to the bits. A 16-bit microprocessor processes 16-bit data at one time. There is a range of the word length in which the data can be varied. It is from 4 bits to 64 bits. It entirely depends on the microcomputer type.
  2. Instruction Set- The microprocessor understands a particular set of instructions. These are contained in this set.
  3. Bandwidth- There is a particular number of instructions which are processed in a single instruction. The bandwidth is the count of that number.
  4. Data Types- There are several types of data which the microprocessor processes. The formats of the data like BCD, ASCII, binary, signed as well as unsigned numbers.
  5. Clock Speed- Clock speed controls the per second work of the processor. That is, it takes the consideration of the number of operations to be done in a time unit. The units which are used to express this are gigabytes and megahertz. The other name of the clock speed is clock rate.

As we have various data types and the functions of the microprocessor, there are numerous characteristics of a microprocessor. It is an extension as well as a prominent list. The elements of the list are as follows-

  • Size- The microprocessor is a chip and that too of small size. This feature makes the microprocessor portable.
  • Cost-Effective- You can buy the chips from the manufacturer on low-costs.
  • Reduced consumption of power- The microprocessor results in the low consumption of energy due to its raw material. It uses the oxide semiconductor technology, and that is why it reaches the level of the consuming less power as compared to the other components of the computer system.
  • Reliable component of the system- You are free and allowed to rely on the microprocessors. It is because of the low rate of failure. The integrated circuit of the microprocessor fails at a very low rate, giving a reliable experience to the user.
  • Adaptability and versatility- You can use the same chip on the different applications. You just have to configure the program of the software to make it versatile.

Classification and the components of the microprocessor

There are three broad categories on which the microprocessor has been classified.

  1. CISC Processor
  2. RISC Processor
  3. Special Processor

 1. CISC Processor

It is the full form of Complex Instruction Set Computer. The primary purpose of the designing of the processor is the minimization of the number of instructions per program. The CISC processor ignores the number count of the cycles of the instructions. It counts on building the complex instructions into the hardware.

Translating the high-level language into the machine and assembly language does not require much work by the compiler. It is because of the shortness of the code length. In this case, very less RAM is needed for the storage of the instructions.

We have various CISC processors with us. For example, VAX 11/780, IBM 370/168, and Intel 80486.

Let us talk about the architecture of the CISC processor.

Architecture of CISC

The primary purpose of this type of the construction is decreasing the cost of the memory. It is because the high amount of storage is required in heavy and cumbersome programs and ultimately it results in the increased and high cost of the memory. To solve the problem, there is a reduction of the instructions per program. It is done by the decrease in the number of operations in a single instruction.

Features of CISC

  • A high count of instructions
  • A diverse range of addressing modules
  • Varied instruction format’s length
  • You need only one instruction for the support of several modules of addressing
  • The operating system needs to work in several cycles for the requirement of the execution of the instruction set.
  1. Special Processors

The processors, as the name suggests do particular purposes. Few of the processes of the processor are

  • Co-processing- math co-processor is the example. Ex- 8087 which is used with 8086. Also, 80287 is another example of the co-processor, and it used with 80286.
  • Input and output processing- For instance, we have DMA, SCSI port controller, Keyboard and mouse controller, and Graphic display controller
  • Transistor computer- In this case, 32-bit T425, and the floating point are a few examples.
  • Digital signal processor- TMS 320C40, and TMS320C50
  1. RISC Processor-

It is the processor named Reduced Instruction Set Computer who has the responsibility of the reduction of the execution time of the instruction to process in the computer. If the processor chooses RISC technique to work, then the system needs only one cycle for the execution of the results in the uniform time of execution.

Processors which uses the RISC technique are-

  • Power PC: 601, 604, 615, 620
  • PA-RISC: HP 7100LC
  • DEC Alpha: 210642, 211066, 21068, 21164
  • MIPS: TS (R10000) RISC Processor

Features of RISC

  • Various data types and their formats are supported
  • Use only simple modes of addressing
  • Have only fixed length instructions for the purpose of the pipelining

The instructions of the computer system which are used to access the memory location are LOAD, STORE