1. CS161 – Design and Architecture of Computer Systems
Spring 2019
Hodjat Asghari Esfeden, Ph.D. Candidate
Department of Computer Science and Engineering,
WCH 459

2. Welcome!

3. About me Born and raised in Iran UC Riverside, CA
PhD Computer Science ’15--present
MSc Computer Science ’17
Sharif University of Technology, Tehran, Iran
BSc Computer Engineering ’15

4. About TA Marcus Chow UC Riverside, CA UC Merced, CA
PhD Computer Science ’16--present
MSc Computer Science ’18
UC Merced, CA
BSc Computer Science ’16

5. Your turn Who you are? Homework 0 (absolutely required)
Your opportunity to tell us about yourself
Due this Thursday, April 4th (midnight)
It’s online on the class website (hodjat.me/teaching/cs161-s19)
Sign up & submit via Piazza (
All grading predicated on receipt of Homework 0

6. What is Computer Architecture?
Hardware organization of computers
how to build computers
Layered view of computer systems
Role of the computer architect:
To make design trade-offs across the hw/sw interface to meet functional, performance and cost requirements

7. So, I hope you are here for:
“C” as a model of computation
Software
Programmer’s view of how
a computer system works
How does an assembly program end up executing as digital logic?
What happens in-between?
How is a computer designed using logic gates and wires to satisfy specific goals?
Architect/microarchitect’s view:
How to design a computer that
meets system design goals.
Choices critically affect both
the SW programmer and
the HW designer
HW designer’s view of how
a computer system works
Hardware
Digital logic as a
model of computation

8. An example: Multi-Core Systems
Chip
CORE 0
L2 CACHE 0
L2 CACHE 1
CORE 1
SHARED L3 CACHE
DRAM INTERFACE
DRAM MEMORY CONTROLLER
DRAM BANKS
CORE 2
L2 CACHE 2
L2 CACHE 3
CORE 3
*Die photo credit: AMD Barcelona

9. Why Computer Architecture?
Again, Computer architecture is the science and art of designing, selecting, and interconnecting hardware components and designing the hardware/software interface to create a computing system that meets functional, performance, energy consumption, cost, and other specific goals.

10. Why Computer Architecture?
Computer Architecture is the glue that binds software and hardware
Enable better systems: make computers faster, cheaper, smaller, more reliable, …
By exploiting advances and changes in underlying technology/circuits
Enable better solutions to problems
Software innovation is built into trends and changes in computer architecture
Understand why computers work the way they do

11. CS161 Goal Teach/enable/empower you to:
Understand how a computing platform (processor + memory + interconnect) works
Familiarity with processor components (pipeline, caches, registers, etc. )
Understand how decisions made in hardware affect the software/programmer as well as hardware designer

12. CS161 Goal (cont’d) Teach/enable/empower you to:
Think critically (in solving problems)
Understand how to analyze and make tradeoffs in design
Provide foundation for further comp arch courses
CS162 – Computer Architecture
CS203 – Advanced Computer Architecture
EE147 – GPU Programming
CS/EE 217 – GPU Architecture

13. Topics Covered Prerequisite: CS/EE 120A Background
Quantifying Performance, Technology Trends, …
Instruction Set Architecture (ISA)
CPU Design
Single cycle, Multi cycle
Processor Pipelining
5-stage pipeline
Memory hierarchy
Memory, Cache, Virtual Memory

14. Logistics Course Website www.hodjat.me/teaching/cs161-s19/
Check often for announcements
Assignments/Projects
Course website & iLearn (iLearn.ucr.edu)
Discussion/Help
Piazza(
Don’t be afraid of asking questions, I will appreciate your curiosity
“S/He who asks a question remains a fool for five minutes. S/He who does not ask remains a fool forever” 
There is a <15 minutes guarantee for the response time

15. Proof?
Spring 2018

16. Proof?
Winter 2019

17. Lecture and discussion location, times
Lectures:
MWF Sproul Hall 1340
Some days, we may have recitation sessions
Discussion sessions:
Tuesday Pierce Hall 3374
Thursday Life Sciences 2418
Goals: to enhance your understanding of the lecture material and help you with the homeworks and exams

18. Tentative course schedule
Tentative schedule is posted in the class website
But don’t believe the “static” schedule
Systems that perform best are usually dynamically scheduled
Static vs. Dynamic scheduling

19. A note on HW vs. SW
This course is classified under “Computer Hardware”
However, you will be much more capable if you master both hardware and software (and the interface between them)
Can develop better software if you understand the underlying hardware
Can design better hardware if you understand what software it will execute
Can design a better computing system if you understand both
This course covers the HW/SW interface and microarchitecture
We will focus on tradeoffs and how they affect software

20. A Note on Books None required
But, I expect you to be resourceful in finding and doing the assignments…
(Optional) Computer Organization and Design, 5th Edition By Patterson and Hennessy

21. Attendance/Grading Attendance Grade Breakdown
You are expected to attend all lectures and discussion.
Some slides only make sense in lecture. 
Grade Breakdown
Homework: 20%
Quizzes: 10%
Midterm: 35%
Final: 35%
Participation: 5%

22. Assignment Policies 10% penalty per late day
If it’s one minute late, it’s still late
No extensions will be given
Assignments: hardcopy of your assignment should be turned in in the class

23. Contact Instructor: Hodjat Asghari Esfeden TA: Marcus Chow
Homepage:
Office: WCH 459
Office Hours: TBD or by appointment
TA: Marcus Chow
Homepage: