8051 Microcontroller: History, Architecture, Applications, and Features

Catalog

Ⅰ Introduction

The 8051 microcontroller series, technically referred to as the Intel MCS-51 Architecture, was developed by Intel in 1980 and was very popular in the 80's (still are popular). In different fields, such as embedded systems, consumer electronics, vehicles, etc., the 8051 Microcontroller is one of the most prominent and most commonly used microcontrollers.

8051 microcontroller

There are several features of the 8051 Microcontroller such as Serial Communication, Timers, Interrupts, etc., and thus many students and beginners begin their work on the 8051 Microcontroller principle of Microcontrollers (although this trend seems to be changed with the introduction of Arduino).

While 8051 Microcontroller can seem a bit out of date, we believe that Microcontrollers, Embedded Systems, and Programming are some of the best platforms to get started with (both C and Assembly).

So, an introduction to the 8051 microcontrollers and some of the fundamentals of the 8051 microcontrollers will be given in this article.

But before we get into the 8051 Microcontroller Introduction and Fundamentals, we need to talk a bit about what a microcontroller is and the distinction between a microprocessor and a microcontroller.

Ⅱ What is a Microcontroller?

A Microcontroller is a VLSI IC that, along with some other peripherals such as memory (RAM and ROM), I/O ports, timers/counters, communication interface, ADC, etc., contains a CPU (processor).

A microprocessor (which was built before the microcontroller) is merely a processor (CPU) and does not have the peripherals mentioned above. We need to independently interface the peripherals to make it functional or create a scheme around it.

Almost all process and control functions were performed using Microprocessors before the advent of Microcontrollers. Although the external peripherals need to operate as a device for the Microprocessor, the average expense of the control system was high.

But the situation, including the field of embedded systems, has changed entirely with the advent of the Microcontroller.

Ⅲ 8051 Microcontroller History

A short description of the 8051 Microcontroller and its past is given in the 8051 Microcontroller Introduction. The Intel 8051 Microcontroller was a successor to the 8048 Microcontroller (Intel MSC-51 Architecture) (Intel MSC-48 Architecture).

8051 Microcontrollers were initially designed using N-MOS technology, but the use of battery-powered systems and their low power consumption contribute to the use of CMOS technology (which is famous for its low power consumption).

While Intel built 8051 microcontrollers (which was discontinued in 2007), 8051 compatible microcontrollers are now being manufactured by more than 20 semiconductor manufacturers, i.e. processors based on the MSC-51 architecture.

Atmel (AT89C51, AT89S51), Phillips (S87C654), STC Micro (STC89C52), Infineon (SAB-C515, XC800), Siemens (SAB-C501), Silicon Labs (C8051), NXP (NXP700, NXP900), etc., are among the 8051 microcontrollers generated by various manufacturers.

Silicon IP Cores (Intellectual Property Cores) are the bulk of the modern 8051 Microcontrollers, but discrete 8051 Microcontroller ICs are also available. 8051 IP Cores are used in FPGAs (Field Programmable Gate Array) and SoCs (System on Chip) instead of Advanced ARM Architecture-based MCUs due to their low power consumption, smaller size, and basic architecture.

Ⅳ 8051 Microcontroller Architecture

8051 microcontroller pin diagram and pin function

CPU (Central Processor Unit):

As you might be conscious, the brain of every processing computer is the Central Processor Unit or CPU. Both processes that are conducted in the Microcontroller are scrutinized and controlled. The operator has no control over the operation of the CPU. It interprets and carries out all of the programs printed in storage space (ROM) and executes the planned task. In the 8051 microcontrollers, the CPU monitors numerous types of registers.

Interrupts:

As the heading put forth, Interrupt is a subroutine call that reads the main function or job of the Microcontroller and allows it to execute any other program that is then extra important. 8051 Interrupt's functionality is highly constructive as it assists in emergency situations. Interrupts provide one with a mechanism for postponing or halting the current operation, executing a sub-routine job, and then restarting the execution of the regular program again.

At the time of the interrupt, the Micro-controller 8051 should be assembled in such a way that it temporarily interrupts or breaks the core program. When the sub-routine assignment is done, the main program execution immediately continues as normal. In the 8051 Microcontroller, there are 5 interrupt supplies, two out of five are peripheral interrupts, two are timer interrupts, and one is serial port interrupt.

Memory:

It is a software that is a series of commands that requires a micro-controller. This software helps the microcontroller to perform particular tasks. Such programs require a storage space on which the Microcontroller can accumulate and interpret them to operate on some particular procedure. The memory that is put into play with the Microcontroller device to generate is known as program memory or code memory. It's also known as Read-Only Memory or ROM.

The microcontroller still requires memory for the short term to amass data or operands. For this primary purpose, the disk space that is used to temporarily store data for service is known as Data Memory and we use Random Access Memory or RAM. The 8051 microcontroller includes 4K code memory or program memory, so it has 4KB ROM and 128 bytes of data memory (RAM) as well.

Bus:

Fundamentally, Bus is a set of wires that serve as a contact channel or a transfer data medium. Such buses are made up of 8, 16 or more wires. A bus will either carry 8 bits or 16 bits overall. Two types of buses exist:

Bus Address: The 8051 microcontroller consists of a 16-bit bus address. For resolving memory locations, it is brought into play. It is often used to relay to Memory the address from the Central Processing Unit.

Data bus: The 8051 microcontroller consists of an 8-bit data bus. It is used for data carting.

Oscillator:

Because we all know that the microcontroller is a piece of equipment for a digital circuit, it needs a timer for its purpose. The Microcontroller 8051 consists of an on-chip oscillator for this purpose, which toils as a CPU time source (Central Processing Unit). As the efficiency thumps of the oscillator are steady as a result, harmonized use of all 8051 Microcontroller parts is encouraged. Input/Output Port: As we know, the microcontroller is used to handle the functions of devices in embedded systems.

We require I/O (input/output) interfacing ports in the Microcontroller to collect them to other devices, gadgets, or peripherals. Micro-controller 8051 consists of 4 input/output ports to connect it to other peripherals for this purpose. Timers/Counters: With two 16 bit counters & timers, Micro-controller 8051 is compatible. The counters would be divided into 8-bit registers. Timers are used to calculate intervals, to figure out the duration of the pulse, etc.

Ⅴ Applications of 8051 Microcontroller

The 8051 Microcontroller is still used in many embedded systems and applications even with the production of many sophisticated and superior microcontrollers.

Any of the 8051 Microcontroller applications are listed below:

Consumer Appliances (TV Tuners, Remote controls, Computers, Sewing Machines, etc.)

Home Applications (TVs, VCR, Video Games, Camcorder, Music Instruments, Home Security Systems, Garage Door Openers, etc.)

Communication Systems (Mobile Phones, Intercoms, Answering Machines, Paging Devices, etc.)

Office (Fax Machines, Printers, Copiers, Laser Printers, etc.)

Automobiles (Air Bags, ABS, Engine Control, Transmission Control, Temperature Control, Keyless Entry, etc)

Aeronautical and Space

Medical Equipment

Defense Systems

Robotics

Industrial Process and Flow Control

Radio and Networking Equipment

Remote Sensing

Ⅵ 8051 Microcontroller Features

8-Bit ALU: ALU is the heart of a microcontroller or Arithmetic Logic Machine. On binary numbers, it executes arithmetic and bitwise operations. The 8051 ALU is an 8-bit ALU, meaning it can run 8-bit data operations.

8-Bit Accumulator: The Accumulator is an essential ALU-related register. An 8-bit register is an accumulator in 8051.

RAM: 8051 There is 128 bytes of RAM on the microcontroller, plus SFRs and Input/Output Port Registers.

ROM: 8051 has an on-chip ROM of 4 KB (Program Memory).

I/O ports: 8051 has four bit-addressable and bidirectional 8-bit input/output ports.

Timers / Counters: There are two 16-bit Timers / Counters in 8051.

Serial Port: Full Duplex UART Connectivity supports 8051.

External Memory: 8051 Two 16 bit address lines can be reached at once by the microcontroller: one for each RAM and ROM. The total external memory that can be accessed by an 8051 Microcontroller for RAM and ROM is 64KB (216 for each type).

Other features: Interrupts, on-chip oscillator, Power Down Mode, Boolean Processor, etc.