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AN887

APPLICATION NOTE

MICROCONTROLLERS MADE EASY

by Microcontroller Division Applications

WHAT IS A MICROCONTROLLER?

A few years ago, system control functions were implemented using logic components and

were usually large, heavy boxes. Later on, microprocessors were used and the entire con-

troller could fit onto a small circuit board. As the process of miniaturization continued, all of the

components needed for a controller were built right onto one chip. By only including the fea-

tures specific to the task, cost is relatively low.

A typical microcontroller has bit manipulation instructions, easy7 and direct access to I/O, and

quick and efficient interrupt processing. Therefore, a microcontroller is a highly integrated

device which includes, on one chip, all or most of the parts needed to perform an application

control function.

Microcontrollers come in many varieties. Depending on the power and features that are

needed, customers might choose a 4, 8, 16, or 32 bit microcontroller.

Figure 1. Typical MCU Block Diagram

ROM (Read Only Memory)

ROM is usually used to store program instructions. ROM is the least expensive mean of

storing a program in a microcontroller, especially for high volume manufacturing.

ROM

RAM

CPU

EEPROM

I/OPORT

SERIAL

TIMER

A / D

CONVERTER

INTERFACE

EXECUTES PROGRAM

MANAGES EVENTS

CONTAINS

PROGRAM

AND DATA

SIGNAL GENERATION

EVENT COUNTING

APPLICATION TIMEBASE

CONTAINS

TEMPORARY

DATA

CONTAINS

PERMANENT

DATA

PERIPHERAL

INTERFACE

ANALOGDATA

ACQUISITION

SENDSAND

RECEIVES

DATA

VR02101A

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