To work with Microcontroller atfirst we should clear our doubt on what is a microcontroller ? And to clear the answer we should know A microcontroller, or MCU, is a computer implemented on a single very large scale integrated (VLSI) circuit. In addition to those components contained in a microprocessor, an MCU also contains some of the following peripheral components:

 • Timers, including event counting, input capture, output compare, real-time interrupt,

and watchdog timer

• Pulse-width modulation (PWM)

• Analog-to-digital converter (ADC)

• Digital-to-analog converter (DAC)

• Parallel I/0 interface

• Asynchronous serial communication interface (UART)

• Synchronous serial communication interfaces (SPI, I2C, and CAN)

• Direct memory access (DMA) controller

• Memory component interface circuitry

• Software debug support hardware

The discussion of the functions and applications of these components is the subject of this text. Most of these functions are discussed in details in later chapters. Since their introduction, MCUs have been used in almost every application that requires certain amount of intelligence. They are used as controllers for displays, printers, keyboards, modems, charge card phones, palm-top computers, and home appliances, such as refrigerators, washing machines, and microwave ovens. They are also used to control the operation of engines and machines in factories. One of the most important applications of MCUs is probably the automobile control. Today, a luxurious car may use more than 100 MCUs. Today, most homes have one or more MCU-controlled consumer electronics appliances. In these applications, people care about only the functionality of the end product rather than the MCUs being used to perform the control function. Products of this nature are often called embedded systems.

Now question is what is Difference between a Microprocessor and Microcontroller ?