This document outlines the first lecture of an introduction to microcontroller systems course. It discusses the course syllabus, policies, and provides an overview of computer architecture history including the Von Neumann and Harvard architectures. Early computing devices like the abacus and Babbage's analytical engine are mentioned. The evolution of microprocessors from the 4004 to modern microcontrollers is covered. Students are assigned homework to define and describe a Turing Machine.

1. ECE 265
Introduction to Microcontroller Based
Systems
(A first course in computer architecture)
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2. © Joanne E. DeGroat, OSU
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
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3. © Joanne E. DeGroat, OSU
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.
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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
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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?????
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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.
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A little more modern
 Charles Babbage 1792-1871
 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 1815-1864
 Boolean Algebra
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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.
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9. © Joanne E. DeGroat, OSU
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
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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
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11. © Joanne E. DeGroat, OSU
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 (1912-1954) work – the Turing Machine
(1936).
 Both von Neumann and Turing wrote papers on
stored program computers.
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12. © Joanne E. DeGroat, OSU
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
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13. © Joanne E. DeGroat, OSU
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.
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The Harvard Architecture
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 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.

15. © Joanne E. DeGroat, OSU
Microprocessor vs.
Microcontroller
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 Basically a features issue.
 Microprocessor – (the physicalpro ce sso r 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

16. © Joanne E. DeGroat, OSU
Lecture summary
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 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

17. © Joanne E. DeGroat, OSU
Assignment
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 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