Difference between 8051 and ARM

Prerequisite – Micro-controller (µC) and Microprocessor (µP) A micro-controller is a single Integrated Circuit 

Introduction :

(IC) which is comparable to little stand alone computer and it is designed to perform the specific tasks of embedded systems. 8051 and ARM comes under the family of micro-controller. 8051 micro-controller and ARM micro-controller differs from each other in terms of different architecture and different sets of instruction, speed, cast, Memory, Power Consumption, Bus Width etc. Now let’s understand in detail what actually they are and how they differs from each other. 

1. 8051 micro-controller : It is a 8 bit family of micro-controller. It is an entry level micro-controller used for most basic applications all across the world and it consumes low power and available with low budget. It was developed by the Intel in the year 1981. 8051 micro-controller has many features like Serial Communication, Timers, Interrupts, etc. This micro-controller is used in various devices and the major areas includes automobiles, medical devices and energy management. Now a days 8051 Micro-controller might seem little bit out of fashion but still it is recommended as best platform to start work on the concept of Micro-controllers with 8051 Micro-controller although this trend seems to be changed with the introduction of Arduino of AVR community.

2. ARM micro-controller : ARM micro-controller was introduced by Acron computer organization and is manufactured by Apple, Nvidia, Qualcomm, Motorola, ST Microelectronics, Samsung Electronics, and TI etc. ARM processor belongs to the family of CPUs which are based on Reduced Instruction Set Computer (RISC) and ARM microprocessor with RAM, ROM and other peripherals in one single chip, we get an ARM micro-controller, for example, LPC2148. It is based on RISC Instruction set Architecture (ISA) and also called as Advanced RISC machine. It is most popular micro controller and most industries use it for embedded systems as it provides large set of features and is good to produce devices with excellent appearances. 
Difference between 8051 and ARM :

S.No.	8051	ARM
1.	8 bit for standard core bus width is present in 8051 micro-controller.	Mostly 32 bit bus width is present in ARM micro-controller and also 64-bit is available.
2.	Its speed is 12 clock cycles per machine cycle.	Its speed is 1 clock cycle per machine cycle.
3.	UART, USART, I2C, SPI, communication protocols are used.	UART, USART, Ethernet, I2S, DSP, SPI, CAN, LIN, I2C communication protocols are used.
4.	Flash, ROM, SRAM memory is used in 8051 micro-controller.	Flash, EEPROM, SDRAM memory is used in ARM micro-controller.
5.	It is based on CISC Instruction set Architecture.	It is based on RISC Instruction Set Architecture.
6.	8051 micro-controller is a Harvard-based architecture, but it allows us to connect external memory and simulate von Neumann’s architecture.	PIC micro-controller is based on Harvard architecture.
7.	Power consumption of 8051 micro-controller is average.	Power consumption of ARM micro-controller is low.
8.	Its families include 8051 variants.	Its families include ARMv4, 5, 6, 7 and cortex series.
9.	Its manufacturers are Atmel, NXP, Silicon Labs, Dallas, Cyprus, Infineon, etc.	Its manufacturers are Nvidia, Qualcomm, Apple, Samsung Electronics, and TI etc.
10.	8051 micro-controller costs very low as compared to features provided.	ARM micro-controller costs low as compared to features provided.
11.	Popular micro-controllers include AT89C51, P89v51, etc.	Popular micro-controllers include ARM Cortex-M0 to ARM Cortex-M7, etc.

Feature	8051	ARM
Architecture	8-bit	32-bit (some models: 64-bit)
CPU Speed	Typically up to 33 MHz	Typically up to 3 GHz
Power Consumption	Higher	Lower
Instruction Set	Limited	More complex and diverse
On-chip memory	Limited	More and larger on-chip memory
On-chip peripherals	Limited	More and diverse on-chip peripherals
Interrupt handling	Simple and limited	More complex and efficient
Development tools	Widely available and mature	Growing ecosystem
Cost	Lower	Higher (compared to low-end 8051)