Final Exam Solution

Your answers should be written in blue (the “Normal” style from the formatting menu).
A typical length of your response is suggested by the title of the section. However, adjust your own response length as needed to answer any given question. As you write, you may push other questions forward along the page. That is expected. However, if it pushes the questions or answers onto a new page, you wrote too much!
Good luck, and don’t forget to submit your Final when you are ready! When you are ready to submit, see instructions on the CI Learn page for this assignment.

One-to-Few Word Answer
General Quick Questions (9 pts)
How many CPUs wgere found in a typical PC from 1980? (1 pt)

How many CPUs were found in a typical PC from 1990? (1 pt)


How many CPUs were found in a typical PC from 2000? (1 pt)


How many CPUs, GPUs, and neural processors (all combined) are found in a typical iPhone X? (Ballpark it.) (2 pts)

Choose one computing device in this room. Name the device and name its architecture. (2 pts)

What would you expect for a typical bus width (the number of data lines) inside a 64-bit CPU vs. a 32-bit CPU? (2 pts)



One-to-Few Word Answer (cont.)
Units of the CPU (7 pts)
Name the unit that manages the rest of them. (1 pt)

Besides setting pins, what else does this unit do? (2 pts)

Name the unit that handles mathematical operations. (2 pt)

Besides mathematical operations, what else does this unit do? (2 pts)

Two-to-Few-Sentence Answer
Class Basics (21 pts)
What is computer organization? (7 pts)


What’s the difference between transistors, logic gates, and logic circuits? (7 pts)
How does (or doesn’t) the control unit of a CPU directly interpret assembly language? Also, how does (or doesn’t) it directly interpret C code? Explain. (7 pts)




Two-to-Few-Sentence Answer (cont.)
Parallel Computing (21 pts)
Why is parallel computing the hot way these days of gaining additional processing power? In your answer, explain why it’s a mixed bag. (7 pts)

Explain the difference between multiprocessing and multithreading. Tie in ideas of shared memory and message passing. (7 pts)

Give one example of a problem that can be tackled with a supercomputer that couldn't be tackled with a distributed network of computers, and very briefly tell what features of the problem make it challenging for distributed computing. (7 pts)




Two-to-Few-Sentence Answer (cont.)
Tiered Memory (21 pts)
What's the primary advantage of having memory caches located so physically close to the processing units? (7 pts)


Discuss at least one non-trivial similarity between a "shared" cache (e.g. the L3 cache) and RAM. (7 pts)

Even in the most high-end computers, RAM doesn't use the highest-speed memory technology available. Why not? (7 pts)


Two-to-Few-Sentence Answer (cont.)
Control Unit (21 pts)
In the John Scott control unit, steps 1 - 3 fetch a single instruction code, and step 7 resets the stepper back to step 1. What happens in step 4 - 6? (You don’t need the diagram to answer this. Note that I’ll be looking for a key word here.) (7 pts)


Writing simple programs from scratch in machine code takes a while and is nearly impossible to read. What's another big reason that programmers don’t choose to write in machine code (or assembly) for general-purpose programs? (7 pts)

What's the difference between a program and a microprogram? (7 pts)

Bonus
Circuitverse (5 bonus pts)
After you have completed and submitted your final exam, but before leaving the classroom, complete this problem (found in our group on Circuitverse) for up to five bonus points:

Make an LED light up for just one clock cycle out of every eight. You can use any CircuitVerse elements you find useful.