ECE 265 Introduction to Microcontroller Based Systems (A first course in computer architecture) 9/28/ ECE265

Lecture Overview  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 9/28/ ECE265

The Syllabus  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. 9/28/ ECE265

General guidelines and policies  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 9/28/ ECE265

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????? 9/28/ ECE265

Early computing technology  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. 9/28/ ECE265

A little more modern  Charles Babbage  The Difference Engine  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  Boolean Algebra 9/28/ ECE265

Still, a little more modern  The von Neumann architecture – 1940s and 50s  A stored-program computer that uses a central processing unit and a single separate storage structure that hold both instructions and data. 9/28/ ECE265

Basic operation of architecture  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 9/28/ ECE265

Decode Instruction and execute  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 9/28/ ECE265

More von Neumann  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 ( ) work – the Turing Machine (1936).  Both von Neumann and Turing wrote papers on stored program computers. 9/28/ ECE265

Some Early von Neumann architectures  ORDVAC (U of Ill)  IAS machine (Princeton)  MANIAC I (Las Alamos)  ILLIAC (U of Ill)  AVIDAC (Argonne National Labs) – 1953  ORACLE at Oak Ridge Ntl Lab– 1953  JOHNNIAC at RAND Corp – 1954  BESK in Stockholm – 1953  PERM in Munich /28/ ECE265

Early Microprocessors  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. 9/28/ ECE265

The Harvard Architecture 9/28/2010ECE  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 1990s)  This is not really a new concept as the 4004 had separate data and program memory address spaces.

Microprocessor vs. Microcontroller 9/28/2010ECE  Basically a features issue.  Microprocessor – (the physical processor chip)  Composed of control unit, register, arithmetic and logic units  NO Memory, MaybeTimers, 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

Lecture summary 9/28/2010ECE  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

Assignment 9/28/2010ECE  What is a Turing machine?  HW1 - Write up what a Turing machine is and how a Turing Machine executes a program. (submit to dropbox HW1) Write 2/3 to 1 ½ pages.  Due dates on web page.  There are many sources for this assignment  Google web search  Wikipedia  Library