Transcript I am an L&S CS major. Why do I have to take this class?

I am an L&S CS major.
Why do I have to take this class?
• So you don’t look stupid when you get to
your job.
• To prepare you for hands-on courses like
CS 150 that involve hardware design.
• Because it’s good to know the physical
basis of computation.
Digital Information
All information inside a
computer is represented
numerically.
 Text: Every letter is
represented by a number
(ASCII code).
 Images: A bitmap image is
a table of numbers, with each
entry representing the color
of a pixel.
{ = 123
Row 3, Column 2 = 00FF44
Number Representation
There are many ways to represent numbers.
 Decimal (base 10, the usual way)
 Hexadecimal (base 16, often used in the
study of computers)
 Binary (base 2)
The ability to represent any number in
binary, using 0’s and 1’s, makes
computation as we know it possible.
High and Low Logic Levels
The numbers 0 and 1 are represented by
physical quantities:
 The number 0 (called logic 0) is
represented with a voltage near 0 V.
 The number 1 (called logic 1) is
represented with a voltage between 2 and
5 V, depending on the technology.
Circuits perform computation by taking
voltage inputs and allowing current to flow,
creating voltage outputs.
A Logic Gate
The mathematical operation known as
“AND” is performed by this circuit:
VDD
VDD
S
S
S
A
D
B
S
S
D
S
AB
Course Content
To analyze the circuits that perform
computation, you need to know about
 Circuit analysis: voltages and currents
so you can see how circuits work,
resistance and capacitance so you see
how long it takes to compute something
 Electronics: transistors which make
complex computation feasible
Devices
We will look inside
 Memories: DRAM, latches, flip-flops…
 A/D and D/A Converters
 Logic Gates
and more!