What is the Difference between 8051, PIC, AVR and ARM?

Nowadays, Microcontrollers are so cheap and simply obtainable that it is general to use them instead of easy logic circuits like counters for the sole reason of gaining some design flexibility and discount some space. Some machines and robots will even rely on a huge number of microcontrollers, each one enthusiastic to a confident task. Mainly fresh microcontrollers are ‘In System Programmable’ it means that you can be adjusting the program being executed, without removing the Microcontroller from its position. In this article we are discussing about the difference between AVR, ARM, 8051 and PIC Microcontrollers.

Difference between AVR, ARM, 8051 and PIC Microcontrollers

The differences between the microcontrollers are mainly include what is a microcontroller, difference between AVR, ARM, 8051 and PIC microcontrollers and its applications.

What is a Microcontroller?

A micro-controller can be comparable to a little stand alone computer; it is an extremely powerful device, which is able of executing a series of pre-programmed tasks and interacting with extra hardware devices. Being packed in a tiny integrated circuit (IC) whose size and weight is regularly negligible, it is becoming the perfect controller for as robots or any machines required some type of intelligent automation. A single microcontroller can be enough to manage a small mobile robot, an automatic washer machine or a security system. Several microcontrollers contains a memory to store the program to be executed, and a lot of input/output lines that can be a used to act jointly with other devices, like reading the state of a sensor or controlling a motor.

8051 Microcontroller

8051 microcontroller is an 8-bit family of microcontroller is developed by the Intel in the year 1981. This is one of the popular families of microcontroller are being used all across the world. This microcontroller was moreover referred as “system on a chip” since it has 128 bytes of RAM, 4Kbytes of a ROM, 2 Timers, 1 Serial port, and 4 ports on a single chip. The CPU can also work for 8bits of data at a time since 8051 is an 8-bit processor. In case the data is bigger than 8 bits, then it has to be broken into parts so that the CPU can process easily. Most manufacturers contain put 4Kbytes of ROM even though the number of ROM can be exceeded up to 64 K bytes.

8051 Microcontroller
8051 Microcontroller

The 8051 has been in utilized in a wide number of devices, mostly because it is easy to integrate into a project or make a device approximately. The following are the major areas of focus:

Energy Management: Efficient metering systems facilitate in controlling energy usage in homes and manufacturing applications. These metering systems are prepared capable by incorporating microcontrollers.

Touch screens: A high number of microcontroller providers incorporate touch-sensing capabilities in their designs. Portable electronics such as cell phones, media players and gaming devices are examples of microcontroller-based touch screens.

Automobiles: The 8051 finds wide taking in providing automobile solutions. They are broadly used in hybrid vehicles to handle engine variants. Furthermore, functions such as cruise control and anti-brake system have been prepared more capable with the use of microcontrollers.

Medical Devices: Moveable medical devices such as blood pressure and glucose monitors use microcontrollers will to show data, thus provided that higher reliability in providing medical results.

PIC Microcontroller

Peripheral Interface Controller (PIC) is microcontroller developed by a Microchip, PIC microcontroller is fast and simple to implement program when we contrast other microcontrollers like 8051. The ease of programming and simple to interfacing with other peripherals PIC become successful microcontroller.

PIC Microcontroller
PIC Microcontroller

We know that microcontroller is an integrated chip which is consists of RAM, ROM, CPU, TIMER and COUNTERS. The PIC is a microcontroller which as well consists of RAM, ROM, CPU, timer, counter, ADC (analog to digital converters), DAC (digital to analog converter). PIC Microcontroller also support the protocols like CAN, SPI, UART for an interfacing with additional peripherals. PIC mostly used to modify Harvard architecture and also supports RISC (Reduced Instruction Set Computer) by the above requirement RISC and Harvard we can simply that PIC is faster than the 8051 based controllers which is prepared up of Von-Newman architecture.

AVR Microcontroller

AVR microcontroller was developed in the year of 1996 by Atmel Corporation. The structural design of AVR was developed by the Alf-Egil Bogen and Vegard Wollan. AVR derives its name from its developers and stands for Alf-Egil Bogen Vegard Wollan RISC microcontroller, also known as Advanced Virtual RISC. The AT90S8515 was the initial microcontroller which was based on the AVR architecture, though the first microcontroller to hit the commercial market was AT90S1200 in the year 1997.

AVR Microocntroller
AVR Microocntroller

AVR Microcontrollers are Available in three Categories

TinyAVR:- Less memory, small size, appropriate just for simpler applications

MegaAVR:- These are the mainly popular ones having a good quantity of memory (up to 256 KB), higher number of inbuilt peripherals and appropriate for modest to complex applications.

XmegaAVR:- Used in commercial for complex applications, which need large program memory and high speed.

ARM Processor

An ARM processor is also one of a family of CPUs based on the RISC (reduced instruction set computer) architecture developed by Advanced RISC Machines (ARM).

ARM Microcontroller
ARM Microcontroller

An ARM makes at 32-bit and 64-bit RISC multi-core processors. RISC processors are designed to perform a smaller number of types of computer instructions so that they can operate at a higher speed, performing extra millions of instructions per second (MIPS). By stripping out unnecessary instructions and optimizing pathways, RISC processors give outstanding performance at a part of the power demand of CISC (complex instruction set computing) procedure.

ARM processors are widely used in customer electronic devices such as smart phones, tablets, multimedia players and other mobile devices, such as wearables. Because of their reduced to instruction set, they need fewer transistors, which enable a smaller die size of the integrated circuitry (IC). The ARM processors, smaller size reduced difficulty and lower power expenditure makes them suitable for increasingly miniaturized devices.

Main Difference between AVR, ARM, 8051 and PIC Microcontrollers






Bus width

8-bit for standard core 8/16/32-bit 8/32-bit 32-bit mostly also available in 64-bit

Communication Protocols

UART, USART,SPI,I2C PIC, UART, USART, LIN, CAN, Ethernet, SPI, I2S UART, USART, SPI, I2C, (special purpose AVR support CAN, USB, Ethernet)

UART, USART, LIN, I2C, SPI, CAN, USB, Ethernet, I2S, DSP, SAI (serial audio interface), IrDA


12 Clock/instruction cycle 4 Clock/instruction cycle 1 clock/  instruction cycle 1 clock/ instruction cycle





Some feature of RISC


Memory Architecture

Von Neumann architecture Harvard architecture Modified Modified Harvard architecture

Power Consumption

Average Low Low Low


8051 variants PIC16,PIC17, PIC18, PIC24, PIC32 Tiny, Atmega, Xmega, special purpose AVR ARMv4,5,6,7 and series


Vast Very Good Very Good Vast


NXP, Atmel, Silicon Labs, Dallas, Cyprus, Infineon, etc. Microchip Average Atmel Apple, Nvidia, Qualcomm, Samsung Electronics, and TI etc.
         Cost (as compared to features provide) Very Low Average Average Low

Other Feature

Known for its Standard Cheap Cheap, effective High speed operation



Popular Microcontrollers

AT89C51, P89v51, etc. PIC18fXX8, PIC16f88X, PIC32MXX Atmega8, 16, 32, Arduino Community LPC2148, ARM Cortex-M0 to ARM Cortex-M7, etc.

Thus, this is all about the difference between AVR, ARM, 8051 and PIC microcontrollers. We hope that you have got a better understanding of this concept. Furthermore, any queries regarding this concept or electronics and electrical projects, please give your valuable suggestions by comment in the comment section below. Here is a question for you, what are the applications of AVR and ARM?


  1. I want to program arduino board using Keil uvision. Can you suggest which version of Keil uvision would be compatible with which arduino board?

    1. Hi Harshita
      I sincerely appreciate your kind response. As per your query, The open-source Arduino Software (IDE) makes it easy to write code and upload it to the board. It runs on Windows, Mac OS X, and Linux. No need of Keil uvision IDE.
      And once again please visit our domestic website http://www.edgefxkits.com/
      For more details please contact to Mr. sathish on +91 8885507011 or you can email us on info@edgefxkits.in

  2. deepika.v says:

    which micro controller is used for digital notice board using gsm sim module, which one is use ?why you taken …..give ellaborate..

Add Comment