Types of Memory unit in Computer Architecture

The internal logic design of a Computer is known as the architecture of the Computer. In the architecture of a Computer, one can see that the Computer consists of a CPU or Microprocessor, Input devices, Output device and Memory. In this article, we are going to discuss different types of Memory unit in Computer architecture.

Contents in this article:

  1. What is the memory in computer?
  2. Use of Memory in a Computer
  3. Types of Memory in Computer
  4. Primary Memory in computer
  5. Secondary Memory in Computer
  6. Cache Memory in computer architecture
  7. Permanent Memory in Computer
  8. Virtual Memory in Computer architecture
  9. Fastest Memory in computer
  10. Unit of Memory in Computer
  11. Memory devices in Computer

What is the Memory in a Computer?

Memory in a Computer is a subsystem of a digital processing system which can store digital data and binary coded instructions. One can imagine a Memory to be made of large number of cells that stores a 0 or a 1 bit. Memory circuit plays an important role in the operation of a Computer.

Use of Memory in a Computer

Memory system in a Computer stores digital data and binary coded instructions in its cells. Total number of cells gives the capacity of the Memory. A Computer needs to communicate with memory and other components to perform a specified program. During the operation Computer reads the instruction from the Memory.

Types of Memory in Computer

Memory elements in a Computer are mainly classified into two categories –

  1. Primary Memory or Main Memory
  2. Secondary Memory
Memory in Computer
Memory in Computer

Apart from that, some other memory elements like resisters, cache memory etc. are available. Most of the memory elements are made of the semiconductors.

Primary Memory in Computer

Computer uses primary storage or main memory to store program and data during their execution. Read only memory (ROM) and Random access memory (RAM) are the main memories in a computer.

Read only Memory (ROM)

A read only memory device can store data permanently in a computer. This is non-volatile type of memory, it can store data even when the power supply is off. One can read out the stored data in any memory location during the normal operation. This is the permanent memory in computer. It is available in the form of IC and can be made by using diode or BJT Transistor or MOSFETs. SD card is an example of ROM. ROM can be programmable (PROM) and erasable (EPROM).

Random Access Memory (RAM)

Random access memory (RAM) is read-write memory. It can store instruction and data temporarily and one can read and write the data in any location of memory. RAM is volatile type of memory. So, it losses the contents after switching off the power supply. There are two types of RAM – Static RAM and dynamic RAM. Static RAM stores data as long as the power supply is on, but the stored data in dynamic RAM gets refreshed periodically.

Secondary Memory in Computer

The main memory (RAM) of a computer is volatile in nature. But, sometime the computer needs to store programs and data for future use. So, in this purpose a computer must have a permanent type of memory. These memories use to store data permanently in a computer are the secondary memories. Some of the examples of Secondary memories are Magnetic hard disk, floppy disk, Compact disk read only memory (CD-ROM) etc. These are the virtual memories in the computer.

Cache memory in Computer architecture

In addition of primary and secondary memories a computer also have Cache memory in the region between CPU and the main memory. Cache memory is a small and high speed memory that stores currently needed instructions and data. It is a good option to increase the speed of operation of a computer without having any expensive resort. Maximum theoretical cache size is 2 MB. Cache memory is the fastest memory in computer system.

Unit of Memory in Computer

Byte, kilobyte (KB), Megabyte (MB), Gigabyte (GB), Terabyte (TB), petabyte (PB) etc. are the units of the memory in computer. We all know that 0 and 1 are the two binary bits. If a memory can store 8 bits the its size will be 1 byte. Because, 8 bits equal to 1 byte. Now if a memory stores 210 bytes then the size of memory is 1 KB.

1 byte (B) = 8 bits

1 KB = 210 bytes or 1024 bytes (B)

Similarly, 1 MB = 210 or 1024 KB , 1 GB = 210 or 1024 MB and so on.

Smallest unit for the size of memory is byte (B) and the largest unit of memory size in computer is Yobibyte (YB).

Memory devices in Computer

Memory are available in the form of devices. SD card, memory card, Hard disk, CD, Pen drive etc. are the memory devices for a computer. There are two types of memory unit in computer – external memory and internal memory. The memory devices mentioned above are the external memories. RAM, ROM, Cache memories are the internal memories of a computer.

Discussion of the summary

A computer needs memory to store instruction and data. It has primary memory (ROM and RAM), secondary memory (Hard disk, floppy disk) and cache memory. The full form of ROM is read only memory and RAM is the read and write memory which has the full form as random access memory. Main purpose of secondary memory is to store data or instruction permanently. Cache memory stores the real time data and increases the speed of the operation or decreases the response time. Size of memory is represented by the unit of byte, KB, MB, GB, TB etc.

  1. ROM is the permanent memory in computer.
  2. Secondary memory is the virtual memory in the computer architecture.
  3. Cache memory is the fastest memory in the computer system.
  4. Resister is the temporary memory unit.

So, in this article, we became to know the different types of memory unit in computer architecture and their uses. If you have any doubt on this topic, you can ask me in the comment section.

Thank you!

Related Posts:

  1. Input devices in computer
  2. Output devices in computer
  3. Basic logic gates with truth table
  4. XOR gate using only NAND or NOR gate

4 thoughts on “Types of Memory unit in Computer Architecture”

  1. Your computer’s main memory is called RAM. You can think of it as a workspace the computer uses to get work done. When you double-click on an app, or open a document, or, well, do much of anything, RAM gets used to store that data while the computer is working on it.


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