CS 250 – Computer Organization & Assembly
Instructor: Paul Anderson
212 JC Long
andersonp@cs.cofc.edu
Lecture slides, labs, and other materials courtesy of
Dr. Michael Raymer, Wright State University, and
Dr. Travis Doom, Wright State University, and
Dr. Sridhar Ramachandran, Indiana University Southeast
College of Charleston, School of Science & Mathematics
Dr. Anderson, Computer Science Department
CS 250
Comp. Org. & Assembly
1
Why study computer organization?
1.
You need to understand hardware to program well.
– Cache thrashing
– Concurrency
– Representations
2.
3.
You need to understand hardware to program correctly.
You need to understand assembly language
(at least every once in a while)
College of Charleston, School of Science & Mathematics
Dr. Anderson, Computer Science Department
CS 250
Comp. Org. & Assembly
2
Black Boxes
The Problem

Every level of this hierarchy that you don’t
understand is a black box
– It might as well be magic
– “Debugging by superstition”
Algorithm & Language

ISA & Microarchitecture
The objective of this course is to move the
black-box boundary down to the
Microarchitecture level!
Circuits & Devices
College of Charleston, School of Science & Mathematics
Dr. Anderson, Computer Science Department
CS 250
Comp. Org. & Assembly
3
The instruction set architecture (ISA)
The Problem


Algorithm & Language
ISA & Microarchitecture
Circuits & Devices
The next step is to translate the program into the
instruction set of the particular computer that will
be used to carry out the work of the program.
The Instruction Set Architecture (ISA) is the
complete specification of the interface between
programs that have been written and the
underlying hardware that must carry out the work
of those programs.
– Examples: IA-32 (Intel, AMD, and others), PowerPC
(Motorola)


Programs are translated from high languages in to
the ISA of the computer on which they will be run
by a program called a compiler (specific to the ISA).
Programs are translated from assembly to the ISA
by an assembler
College of Charleston, School of Science & Mathematics
Dr. Anderson, Computer Science Department
CS 250
Comp. Org. & Assembly
4
The microarchitecture
The Problem
Algorithm & Language

The next step is to transform the ISA into an
implementation. The detailed organization of an
implementation is called its microarchitecture.
– The IA-32 has been implemented by several different
processors over the past twenty years 8086 (Intel,
1979), 8286, 8386, 8486, Pentium, Pentium II, Athlon,
Pentium III.
– Each implementation is an opportunity for computer
designers to make different trade-offs between cost
and performance. [Computer design is always an
exercise in trade-offs.]
ISA & Microarchitecture
Circuits & Devices
College of Charleston, School of Science & Mathematics
Dr. Anderson, Computer Science Department
CS 250
Comp. Org. & Assembly
5
The logic circuit
The Problem


Algorithm & Language

ISA & Microarchitecture
The next step is to implement each element of
the microprocessor out of simple logic circuits.
Here there are also choices, as the logic
designer decides how to best make the tradeoffs between cost and performance.
Even in the case of addition, there are several
choices of logic circuits to perform this
operation and differing speeds and
corresponding costs.
Circuits & Devices
College of Charleston, School of Science & Mathematics
Dr. Anderson, Computer Science Department
CS 250
Comp. Org. & Assembly
6
The devices
The Problem


Algorithm & Language
Finally, each basic logic circuit is implemented
in accordance with the requirements of the
particular device technology used.
So, CMOS circuits are different from NMOS
circuits, which are different, in turn, from
gallium arsenide circuits.
Vcc
Rc
ISA & Microarchitecture
Vin
Circuits & Devices
College of Charleston, School of Science & Mathematics
Dr. Anderson, Computer Science Department
Vout
Rb
GND
CS 250
Comp. Org. & Assembly
7
CS Realities

You’ve got to understand binary encodings
–
–
–
–

Integers
Floats
Characters
Instructions
You’ve got to understand how a machine processes instructions
– The stack

You have to understand memory
– Memory references (pointers)

Computers do more than execute your program
– I/O
– Interrupts
– Network behavior

In short:
– You must understand the system in order to optimize performance!
College of Charleston, School of Science & Mathematics
Dr. Anderson, Computer Science Department
CS 250
Comp. Org. & Assembly
8
Understanding your hardware
Intel® Core™ i7-3930K Processor
(12M Cache, 3.20 GHz)
# of Cores
6
# of Threads
12
Clock Speed
3.2 GHz
Max Turbo Frequency
3.8 GHz
Intel® Smart Cache
12 MB
Bus/Core Ratio
57
Instruction Set
64-bit
Lithography
32nm
Recommended Customer Price
$583 - $594
Idle States
Yes
Enhanced Intel SpeedStep® Technology Yes
Execute Disable Bit
Yes
College of Charleston, School of Science & Mathematics
Dr. Anderson, Computer Science Department
CS 250
Comp. Org. & Assembly
9
Where we are heading
College of Charleston, School of Science & Mathematics
Dr. Anderson, Computer Science Department
CS 250
Comp. Org. & Assembly
10