Thursday, June 12, 2014

What is a microcontroller

In the first chapter we will discuss about - what is a micro controller?

So first let me tell you what is the difference between an IC and a micro controller or what is the difference between normal IC controlled circuit and a micro controller controlled circuit.

A normal IC is or integrated circuit , sometimes called a chip or microchip, is a semiconductor wafer on which thousands or millions of tiny resistors, capacitors, and transistors are fabricated. An IC can function as an amplifier, oscillator, timer, counter, computer memory, or microprocessor. A particular IC is categorized as either linear (analog) or digital, depending on its intended application.
Such an IC is pre programmed or the purpose of its application is defined by the manufactures and those IC's can be used only for that purpose.

Now come to micro controller

A micro controller is a small, low-cost computer-on-a-chip which usually
  • An 8 or 16 bit microprocessor (CPU)
  • A small amount of RAM
  • Programmable ROM and/or flash memory
  • Parallel and/or serial I/O
  • Timers and signal generators
  • Analog to Digital (A/D) and/or Digital to Analog (D/A) conversion.
 In a micro controller, the device is user programmable. That is the user can write programs as per his needs and can be loaded into the micro controller. So a single micro controller can be used for various purposes by changing the program written into it.  
It is also called embedded controllers, because the micro controller and support circuits are often built into, or embedded in, the devices they control.Embedded products are designed to allow the user to provide input and receive results.

Basic structure of a micro controller 

Block diagram explanation:

Crystal oscillator:- It has the same function as that of a human heart. It generates the clock pulses through which the entire functions of the micro controller are carried out.

ADC/DAC:- Since the micro controller is a digital device, the ADC/DAC port/pin is used for interfacing the external analog devices

Timers/Counters:- The timer TMR0 has a wide range of applications in practice. Very few programs don't use it in some way. It is very convenient and easy to use for writing programs or subroutines for generating pulses of arbitrary duration, time measurement or counting external pulses (events) with almost no limitations.

Parallel I/O ports:- have a wide range of alternative functions:
  UART                           Universal asynchronous receiver/transmitter

  SSI                                Synchronous serial interface

  I2C                                Inter-integrated circuit

  Timer                            Periodic interrupts, input capture, and output compare

  PWM                            Pulse width modulation

  ADC                              Analog to digital converter, measure analog signals

  Analog Comparator      Compare two analog signals

  QEI                              Quadrature encoder interface

  USB                              Universal serial bus

  Ethernet                        High-speed network

  CAN                             Controller area network

Detailed explanation of the block diagram will be published in the following posts, thank you.

tags: embedded for beginners, embedded tutorials, micro controller tutorials, micro controller basics, micro controller tutorials, micro controller basics


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