Digital Electronics: Principles, Devices and Applications

14

Microcontrollers

Microcontrollers are hidden inside almost every product or device with which its user can interact. In fact, any device that has a remote control or has an LED/LCD screen and a keypad has an embedded microcontroller. Some common products where one is sure to find the use of a microcontroller include automobiles, microwave ovens, TVs, VCRs, high-end stereo systems, camcorders, digital cameras, washing machines, laser printers, telephone sets with caller ID facility, mobile phones, refrigerators and so on. This chapter focuses on microcontroller fundamentals and the application-related aspects of it. Beginning with an introductory description of the device, with particular reference to its comparison with a microprocessor, the chapter covers the general architecture and the criteria to be followed to choose the right device for a given application. This is followed by application-relevant information, such as salient features, pin configuration, internal architecture, etc., of popular brands of eight-bit, 16-bit, 32-bit and 64-bit microcontrollers from major international manufacturers. Intel's 8051 family of microcontrollers is described in more detail.

14.1 Introduction to the Microcontroller

The microcontroller may be considered as a specialized computer-on-a-chip or a single-chip computer. The word ‘micro’ suggests that the device is small, and the word ‘controller’ suggests that the device may be used to control one or more functions of objects, processes ...