ece 3561 - lecture 1 1 introduction to microcontrolllers department of electrical and computer...

ECE 3561 - Lecture 1 1

Introduction to Microcontrolllers

Department of Electrical and Computer EngineeringThe Ohio State University

ECE 2560

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Today

The CourseSyllabusIntro

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Course Philosophy and Objective

Familiarize students the architecture, programming and use of a microcontroller.

Learn to use an actual microcontrollerLearn modern design technologies Learn what assembler language is

Embedded Systems

Chapter 1 of textMicrocontrollers are an efficient mean by

which an embedded system can be implemented.

Microcontroller include (on board)ProcessorMemoryClock I/O support and usually A-to-D conversion

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An Embedded System?

What is an embedded system? Not a personal computer!!! A cooking timer The burner and oven controller in your stove The ABS controller in you car The landing gear control system on a plane

Features of an embedded system Very focused function Usually part of a larger system

Most systems today rely on digital control

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Examples

There are about 100 embedded processors in each PC, not just the main processor.

A car today has about 100 embedded processors. (ABS, sound system, engine control, emissions control, …)

Electric tootbrushWashers and Dryers

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Examples

Washer/Dryer

Others???

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A system to design

A possible implementation

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Salter kitchen scale

An implementation

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Tradeoff for systems

Could implement the system with discrete gates, an FPGA, microcontroller

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Microcontrollers

History 101 Early device – Intel 4004 – 4 bit microprocessor

– no onboard memory, timers, I/O supportOver time

On board memory, timers, A-to-D, etc microcontroller

Microcontroller has little if any OS support. Many have development systems.

Microcontroller “OS” is typically a RTOS.

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Microcontroller

The Core

CPU (ALU, registers)Memory – program and data I/O ports Internal address and data bussesClock

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Added to core

Watchdog timerCommunication interfacesNonvolatile memory for dataA-to-D converterD-to-A converterReal-time clockMonitor, background debugger,

embedded emulator

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Memory

Contains the binary information and typically addressed as bytes (words)

The information stored there can be data or instructions

In many microcontrollers instruction memory is stored in one-time or flash programmable memory.

Addresses and contents typically expressed in hexadecimal

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Volatile and nonvolatile memory

Volatile – content is lost when power is removed – goes to 0’s

Nonvolatile – content is retainedMasked ROM – manufacturedPROM – Programmable Read Only Memory

One time (OTP)Programmable (UV erasable) EPROMFlash – EEPROM – uses a higher voltage to

write contents

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von Neumann Architecture

Traditional architecture

Diagram validforHarvard Archtoo

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Harvard arch

Note diagrams

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The MSP430

Introduced in the late 1990s16-bit von Neumann architecture – both

address and dataLow powerRISC type architectureNo pages or banks in memory making it

simple to use.Can be programmed in CHas 16 registers in CPU

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Assignment

Read Chapter 1 and 2Assignments will be due 2 classes after

assigned to the drop box on Carmen. No paper submissions – all are electronic.

Go to ti.com and get code composer for the MSP430 – when downloaded and installed, run the 10 minutes tutorial.

Also, buy the TI launchpad – $9.99

Code composer startup

The startup Screen on Windows

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