ECE 265 Introduction to Microcontroller Based Systems A

ECE 265 Introduction to Microcontroller Based Systems (A first course in computer architecture) 9/28/2010 1

Lecture Overview 2 Outline of the course Syllabus General guidelines and policies A basic overview of computer architecture The Von Neumann Architecture The Harvard architecture Microprocessors and Microcontrollers ECE 265 9/28/2010

The Syllabus 3 This is ECE 265 – Introduction to Microprocessor Based Systems Objective – A basic understanding of computer architecture, specifically microcontrollers, along with an understanding of the uses and application of microcontrollers. ECE 265 9/28/2010

General guidelines and policies 4 Generally a quiz each week. Typically on Wednesday. Quiz will not necessarily be announced each week. Lowest Grade dropped. NO MAKEUP QUIZZES Homework due two classes after assigned. NO LATE HOMEWORKS will be accepted. Homework will be delivered to a dropbox in CARMEN. Dropbox will not close but no submissions after due date will be graded. Midterm exam will be announced one week prior. Final exam is during Finals Week Monday March 12 11: 30 -1: 18 in this room. Other details on syllabus ECE 265 9/28/2010

5 A Basic Overview of Computer Architecture For your reference you can find much of this information on Wikipedia. But can you trust wikipedia? When was the first computer created? ? ? ECE 265 9/28/2010

Early computing technology 6 Early computing could be traced back to the abacus. When was the abacus in use? Around 2700 B. C. In the mid 1600’s Blaise Pascal designed and implemented a mechanical calculator. Note: Today we use voltage level to represent a logical TRUE and FALSE. There is no reason that the physical position of a mechanical component cannot do the same thing. ECE 265 9/28/2010

A little more modern 7 Charles Babbage 1792 -1871 The Difference Engine 2 Basically a programmable calculator Calculated artillery tables The Analytic Engine – a more advanced machine Used punch cards for input A precursor to the modern computer Boole 1815 -1864 Boolean Algebra ECE 265 9/28/2010

Still, a little more modern 8 The von Neumann architecture – 1940 s and 50 s A stored-program computer that uses a central processing unit and a single separate storage structure that hold both instructions and data. ECE 265 9/28/2010

Basic operation of architecture 9 Instructions are executed in sequence First step during execution MEM(PC) IR Send contents of PC (Program counter) to memory Memory responds with the contents at that address placing it on the data bus. Increment the PC (PC+1 ->PC) The values on the data bus are loaded into the instruction register ECE 265 9/28/2010

Decode Instruction and execute 10 Say the instruction was a load immediate This means that the next word in the instruction stream is the data that we want loaded into the accumulator Operation is now MEM(PC) Accum Also increment the PC ECE 265 9/28/2010

More von Neumann 11 Earliest computers had fixed programs – such as a desk calculator The von Neumann architecture introduced the concept of a stored program. In fact, in early computers, they often wrote programs that self modified. Self-modifying code is now seen as a very bad programming practice (also, it really isn’t needed). von Neumann’s was very familiar with Alan Turing’s (1912 -1954) work – the Turing Machine (1936). Both von Neumann and Turing wrote papers on stored program computers. ECE 265 9/28/2010

12 Some Early von Neumann architectures ORDVAC (U of Ill) - 1951 IAS machine (Princeton) - 1952 MANIAC I (Las Alamos) - 1952 ILLIAC (U of Ill) - 1952 AVIDAC (Argonne National Labs) – 1953 ORACLE at Oak Ridge Ntl Lab– 1953 JOHNNIAC at RAND Corp – 1954 BESK in Stockholm – 1953 PERM in Munich - 1956 ECE 265 9/28/2010

Early Microprocessors 13 The Intel 4004 – 1971 16 -pin DIP package 92, 000 instructions per sec 10. 8 microseconds per instruction Processor had a small address space for data and a small address space for instructions Designed for use in calculators Was the core element for the early electronic calculators – early calculators did basic arithmetic. Early microprocessors were often programmed in assembler or machine code. Compilers and many modern high level programming languages just didn’t exist. ECE 265 9/28/2010

The Harvard Architecture 14 In the traditional von Neumann architecture memory holds both programs and data In the Harvard Architecture you have separate memory spaces for data and programs. (term that came into use during the late 1990 s) This is not really a new concept as the 4004 had separate data and program memory address spaces. ECE 265 9/28/2010

15 Microprocessor vs. Microcontroller Basically a features issue. Microprocessor – (the physical processor chip) Composed of control unit, register, arithmetic and logic units NO Memory, Maybe. Timers, No direct external I/O ports Does have pins for a data bus and an address bus When implemented in a PC, add a keyboard for input, a monitor, a mouse, a printer, etc. Mircocontroller Central core of microprocessor but limited capabilities in regards to registers, memory size, and speed. On board memory Several Timers I/O configurable ports In implementation, may or may not have a keyboard, rather a keypad/switches for input or other types of control, often does not have monitor ECE 265 9/28/2010

Lecture summary 16 Have covered What will be covered by this course and how the course will operate The syllabus, general guidelines and policies An introduction to the history of computing – computer are not new The von Neumann architecture Other architecture focuses ECE 265 9/28/2010

Assignment 17 What is a Turing machine? HW 1 - Write up what a Turing machine is and how a Turing Machine executes a program. (submit to dropbox HW 1) Write 2/3 to 1 ½ pages. Due dates on web page. There are many sources for this assignment Google web search Wikipedia Library ECE 265 9/28/2010