Stamatis Vassiliadis

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Computer Engineering What is it, anyway?

• Stamatis Vassiliadis

CARDIT
ITS
TU Delft
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Some Expectations
EE Electrical Engineers CE Computer
Engineers CS Computer Scientists SA System
Analysts CP Computer Programmers
Number of positions
927954 (SA)
601232 (CP)
536730
482936
417223 (EE)
371785 (CE)
282865 (CS)
348657
195228
149342
Year
1994
2004
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Some Expectations
EE Electrical Engineers CE Computer
Engineers CS Computer Scientists SA System
Analysts CP Computer Programmers
Relative Increases
1.92 (SA)
1.90 (CE)
1.89 (CS)
1.20 (EE)
1.12 (CP)
1.000
Year
1994
2004
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Computer Engineering Analysis of data
processing requirements for electronic data
processing units and systems and the design
(synthesis) of their architecture, implementation
and realization.
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Organization

• What is Computer Engineering?
• Partitioning of Computer Engineering
• Conclusion

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What Does It Really Mean?

• Determine the function to perform

? Architecture

• Establish a method to achieve the function

? Implementation

• Use available means to materialize the method

? Realization
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General Engineering Concept
(Architecture)
Architecture of an analog clock

• Divide dial into 12ths and 60ths

• Have a short hand that goes
• around 2 times (hours)

• Have a long hand that goes
• around 12 times faster (minutes)

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Several Variants
For example

• Ignore the shapes and lengths

• Do not mark the minutes

• Label the hours with arabic numbers

or roman numbers
NOTE Analog clock architecture ?
Digital clock architecture
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More Variants?
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Clock Architecture
What is it?
It specifies the conceptual structure and
functional behaviour as perceived by its user.
Notes

• Inner structure is not specified
• Materialization is not specified

Not needed to tell the time!
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Computer Architecture

• Conceptual structure

• of bits per word (16 bits, 32 bits, ...)
• bit arrangement (MSB, LSB, ...)
• virtual memory

Examples

• Behaviour

• instructions
• arithmetic

Examples
HOW DO WE DEFINE AN ARCHITECTURE?
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Addition as an Example

• Conceptual structure

• of bits 8
• notation binary
• bit arrangement most significant bit first,
• first bit is the sign

5 0 0 0 0 0 1 0 1 5 000022020
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Addition as an Example

• Behaviour

• Numbers are added and produce binary numbers
• 110 carry 1
• 10011 carry 0
• 000 carry 0
• The notation is 2s complement
• Overflow signifies illegal addition
  create an interrupt

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General Engineering Concept
(Implementation)
It tells us how it happens!
Clock architecture has hundreds of
implementations!

• Weight, driving a pendulum
• Spring, driving a wheel
• Battery, driving quartz oscilator
• ...

Examples
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General Engineering Concept
(Implementation)
What is determined in an implementation?
Implementation is the logical organization of the
inner structure of a designed object

• Period of a pendulum
• Number of gears
• Number of teeth
• How are the components connected

Example
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Computer Implementation
(Addition)
1
1
1
0 0 0 0 1 0 1 5 0 0 0 0 1 1 1 7

0
1
0
1
0 0 0
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What should we do?
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Computer Implementation
(Addition)
Two different implementations
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Computer Enigineering Concepts
(Realization)
Realization of a clock.

• period of the pendulum
• number of teeth of the gears

• Given

• decide where to place them (sometimes part of
  implementation)
• decide which material to use
• tolerances, manufacturing, etc..

• Do

END PRODUCT ? CLOCK
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Computer Enigineering Concepts
(Realization)
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From Architecture to Realization
Conclusion
Implementation
Realization
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What is this?
This is NOT a clock!
This is the anticythera mechanism.
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