Introduction to Microcontroller Based System

1. ECE 265
Introduction to Microcontroller Based
Systems
(A first course in computer architecture)
9/28/2010
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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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8. © Joanne E. DeGroat, OSU
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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14. © Joanne E. DeGroat, OSU
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