1. COSC 3406: Computer Organization
Kalpdrum Passi
( )

2. Morgan Kaufmann Publishers Computer Abstractions and Technology
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Chapter 1
Computer Abstractions and Technology

3. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Below Your Program
Application software
Written in high-level language
System software
Compiler: translates HLL code to machine code
Operating System: service code
Handling input/output
Managing memory and storage
Scheduling tasks & sharing resources
Hardware
Processor, memory, I/O controllers

4. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Levels of Program Code
High-level language
Level of abstraction closer to problem domain
Provides for productivity and portability
Assembly language
Textual representation of instructions
Hardware representation
Binary digits (bits)
Encoded instructions and data

5. Levels of Representation
temp = v[k];
v[k] = v[k+1];
v[k+1] = temp;
High Level Language Program (e.g., C)
Compiler
lw $t0, 0($2)
lw $t1, 4($2)
sw $t1, 0($2)
sw $t0, 4($2)
Assembly Language Program (e.g.,MIPS)
Assembler
Machine Language Program (MIPS)
Machine Interpretation
wire [31:0] dataBus;
regFile registers (databus);
ALU ALUBlock (inA, inB, databus);
Hardware Architecture Description (e.g., Verilog Language)
Architecture Implementation
wire w0;
XOR (w0, a, b);
AND (s, w0, a);
Logic Circuit Description (Verilog Language)

6. Components of a Computer
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Components of a Computer
§1.4 Under the Covers
Same components for all kinds of computer
Desktop, server, embedded
Input/output includes
User-interface devices
Display, keyboard, mouse
Storage devices
Hard disk, CD/DVD, flash
Network adapters
For communicating with other computers
The BIG Picture

7. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Touchscreen
PostPC device
Supersedes keyboard and mouse
Resistive and Capacitive types
Most tablets, smart phones use capacitive
Capacitive allows multiple touches simultaneously

8. Through the Looking Glass
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Through the Looking Glass
LCD screen: picture elements (pixels)
Mirrors content of frame buffer memory

9. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
Morgan Kaufmann Publishers
November 11, 2018
Opening the Box
Capacitive multitouch LCD screen
3.8 V, 25 Watt-hour battery
Computer board
Integrated Circuits

10. Inside the Processor (CPU)
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Inside the Processor (CPU)
Datapath: performs operations on data
Control: sequences datapath, memory, ...
Cache memory
Small fast SRAM memory for immediate access to data

11. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Inside the Processor
Apple A5

12. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Abstractions
The BIG Picture
Abstraction helps us deal with complexity
Hide lower-level detail
Instruction set architecture (ISA)
The hardware/software interface
Application binary interface (ABI)
The ISA plus system software interface (operating system)
Implementation
The details underlying and interface
Hardware that obeys the architecture abstraction

13. Abstractions Instruction Set Architecture or architecture (ISA)
Interface between hardware and the lowest-level software
Anything programmers need to know to make a binary machine language program work correctly
Application Binary Interface (ABI)
Combination of basic instruction set and the operating system interface provided for application programmers
Architecture Vs Organization
Architecture (ISA) – abstraction
Organization – implementation of ISA in hardware

14. Overview of Physical Implementations
The hardware out of which we make systems.
Integrated Circuits (ICs)
Combinational logic circuits, memory elements, analog interfaces.
Printed Circuits (PC) boards
substrate for ICs and interconnection, distribution of CLK, Vdd, and GND signals, heat dissipation.
Power Supplies
Converts line AC voltage to regulated DC low voltage levels.
Chassis (rack, card case, ...)
holds boards, power supply, provides physical interface to user or other systems.
Connectors and Cables.

15. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
A Safe Place for Data
Volatile main memory
Loses instructions and data when power off
Non-volatile secondary memory
Magnetic disk
Flash memory
Optical disk (CDROM, DVD)

16. Great Idea: Principle of Locality/ Memory Hierarchy
11/11/2018 16

17. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Networks
Communication, resource sharing, nonlocal access
Local area network (LAN): Ethernet
Wide area network (WAN): the Internet
Wireless network: WiFi, Bluetooth

18. Morgan Kaufmann Publishers
November 11, 2018
Chapter 1 — Computer Abstractions and Technology
Technology Trends
Electronics technology continues to evolve
Increased capacity and performance
Reduced cost
§1.5 Technologies for Building Processors and Memory
DRAM capacity
Year
Technology
Relative performance/cost
1951
Vacuum tube 1
1965
Transistor 35
1975
Integrated circuit (IC)
900
1995
Very large scale IC (VLSI)
2,400,000
2013
Ultra large scale IC
250,000,000,000

19. Semiconductor Technology
Silicon: semiconductor (found in sand)
Add materials to transform properties:
Conductors (using either microscopic copper or aluminum wire)
Insulators (like plastic sheathing or glass)
Switch (Areas that can conduct or insulate under specific conditions)
Transistors fall into the last category.
A VLSI circuit, is just billions of combinations of conductors, insulators, and switches manufactured in a single small package.

20. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Manufacturing ICs
Yield: proportion of working dies per wafer

21. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Intel Core i7 Wafer
300mm wafer, 280 chips, 32nm technology
Each chip is 20.7 x 10.5 mm

22. Integrated Circuit Cost
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Integrated Circuit Cost
Nonlinear relation to area and defect rate
Wafer cost and area are fixed
Defect rate determined by manufacturing process
Die area determined by architecture and circuit design

23. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Defining Performance
§1.6 Performance
Which airplane has the best performance?

24. Response Time and Throughput
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Response Time and Throughput
Response time
How long it takes to do a task
Throughput
Total work done per unit time
e.g., tasks/transactions/… per hour
How are response time and throughput affected by
Replacing the processor with a faster version?
Adding more processors?
We’ll focus on response time for now…

25. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Relative Performance
Define Performance = 1/Execution Time
“X is n time faster than Y”
Example: time taken to run a program
10s on A, 15s on B
Execution TimeB / Execution TimeA = 15s / 10s = 1.5
So A is 1.5 times faster than B

26. Measuring Execution Time
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
Measuring Execution Time
Elapsed time
Total response time, including all aspects
Processing, I/O, OS overhead, idle time
Determines system performance
CPU time
Time spent processing a given job
Discounts I/O time, other jobs’ shares
Comprises user CPU time and system CPU time
Different programs are affected differently by CPU and system performance

27. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
Morgan Kaufmann Publishers
November 11, 2018
CPU Clocking
Operation of digital hardware governed by a constant-rate clock
Clock period
Clock (cycles)
Data transfer and computation
Update state
Clock period: duration of a clock cycle
e.g., 250ps = 0.25ns = 250×10–12s
Clock frequency (rate): cycles per second
e.g., 4.0GHz = 4000MHz = 4.0×109Hz

28. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
CPU Time
Performance improved by
Reducing number of clock cycles
Increasing clock rate
Hardware designer must often trade off clock rate against cycle count

29. Morgan Kaufmann Publishers
Chapter 1 — Computer Abstractions and Technology
November 11, 2018
Morgan Kaufmann Publishers
CPU Time Example
Computer A: 2GHz clock, 10s CPU time
Designing Computer B
Aim for 6s CPU time
Can do faster clock, but causes 1.2 × clock cycles
How fast must Computer B clock be?