8051 Micro-Controller

Microcontrollers: It is a programmable integrated circuit (IC) that consists of a small CPU, RAM and I/O pins. Microcontroller units (MCUs) are widely used in many devices.

A microcontroller is a small and low-cost microcomputer, which is designed to perform the specific tasks of embedded systems like displaying microwave’s information, receiving remote signals, etc.

The 8051 microcontroller was invented in 1980’s by Intel. Its foundation is based on Harvard architecture and this microcontroller was developed principally for bringing it to be used in Embedded Systems. At first it was created by using NMOS technology but the use of NMOS consumed more power to work therefore Intel re-launch the microcontroller 8051 using CMOS technology and new edition came up with edition of letter ‘C’ in the title name, therefore the new modified version of microcontroller is called by name 80C51. The 8051 microcontroller programming is performed in embedded C language using Keil software.

Some Features of 8051 Micro-Controller are:

  • It having four register banks
  • 64K bytes on-chip programmable memory (ROM)
  • 128 bytes on-chip data memory (RAM)
  • Address bus is 16-bit unidirectional
  • Data bus is 8-bit bidirectional
  • 128 user defined flags
  • 16 bit timers
  • 32 general purpose registers each of 8-bit
  • 8051 microcontroller offers a number of special features such as ADC, UARTs, Op-amp, etc.

Architect of 8051 Microprocessor

Block Diagram of Internal Architect of 8051 Micro- Controller

CPU (Central Processing Unit): CPU act as a mind of any processing machine. It synchronizes and manages all processes that are carried out in microcontroller. User has no power to control the functioning of CPU. It interprets the program stored in ROM and carries out from storage and then performs it projected duty. CPU manage the different types of registers available in 8051 microcontroller.

Interrupts: Interrupts is a sub-routine call that given by the microcontroller when some other program with high priority is request for acquiring the system buses the n interrupts occur in current running program.

Types of interrupt in 8051 Microcontroller:

  • Timer 0 overflow interrupt – TF0
  • Timer 1 overflow interrupt – TF1
  • External hardware interrupt – INT0
  • External hardware interrupt – INT1
  • Serial communication interrupt – RI/TI

Memory: For operation Micro-controller required a program. This program guides the microcontroller to perform the specific tasks. This program installed in microcontroller required some on chip memory for the storage of the program. Microcontroller also required memory for storage of data and operands for the short duration. In microcontroller 8051 there is code or program memory of 4 KB that is it has 4 KB ROM and it also comprise of data memory (RAM) of 128 bytes.

Bus : Bus is a group of wires which uses as a communication canal or acts as means of data transfer. The different bus configuration includes 8, 16 or more cables. Therefore, a bus can bear 8 bits, 16 bits all together. The two types of bus used in 8051 microcontroller:

  • Address Bus: 8051 microcontrollers is consisting of 16 bit address bus. It is generally be used for transferring the data from Central Processing Unit to Memory.
  • Data bus: 8051 microcontroller is consisting of 8 bits data bus. It is generally be used for transferring the data from one peripherals position to other peripherals.

Oscillator: As the microcontroller is digital circuit therefore it needs timer for their operation. To perform timer operation inside microcontroller it required externally connected or on-chip oscillator. Microcontroller is used inside an embedded system for managing the function of devices. Therefore, 8051 uses the two 16 bit counters and timers. For the operation of this timers and counters the oscillator is used inside microcontroller.

Application of 8051 Microcontroller:

The 8051 microcontroller applications include a large amount of machines because it is used for incorporating inside a project or to assemble a machine using it. The major applications of 8051 Microcontroller:

  1. Energy Management : In energy management system the measuring device is used for calculating the energy consumption in industrialized and domestic applications. These systems are manufactured by integrating the microcontrollers inside their architecture configuration.
  2. Automobiles : Microcontroller 8051 is to be used for providing automobile solutions. They are largely be used in hybrid motor vehicles to control engine variations.
  3. Touch screens: The advanced degree of microcontroller integrate the touch sensing ability within their design .Transportable devices such as cell phones, media players and gaming devices are some example of microcontroller integrated with touch screens.
  4. Medical Devices: Microcontroller is used in various medical devices such as glucose and blood pressure measurement machine for monitoring and measuring the exact result in real-time computational environment.