CSCI 2321 (Computer Design), Spring 2021:
Homework 7
- Credit:
- 20 points.
Be sure you have read, or at least skimmed, the assigned sections
of Chapter 4 of the text, starting with 4.6.
Answer the following questions. You may write out your answers by
hand and scan them, or you may use a word processor
or other program, but please submit a PDF or plain text
via e-mail to my TMail address.
(No links to shared files on Google Drive please.)
Please use a subject line that mentions the course and
the assignment (e.g.,
“csci 2321 hw 7” or
“computer design hw 7”).
- (15 points)
We have looked at two implementations for a subset of the MIPS
instruction set architecture, single-cycle and pipelined.
For each of the following statements, say whether it is
true or false and why.
(Hint: None of these are intended to be trick questions.)
- The cycle time for the pipelined implementation
will probably be shorter than for the single-cycle
implementation.
(Recall from Chapter 1 that cycle time and
time to execute an instruction might or might not
be the same.)
- All instructions take the same amount of time in
the single-cycle implementation
(counting from when the instruction begins
to when the next instruction begins).
- All instructions take the same amount of time in
the pipelined implementation
(meaning from the time the instruction is fetched
from memory to the time it completes),
if control and data hazards are ignored.
- All instructions take the same amount of time in
the pipelined implementation
(meaning from the time the instruction is fetched
from memory to
the time it completes),
if control and data hazards are NOT ignored.
- Most programs will probably run faster on the
pipelined implementation.
- Aside from possible differences in execution time,
programs will run the same way
(in the sense of giving the same results)
on both implementations.
(You can assume that the hardware correctly
resolves any control and data hazards --
if it doesn't, it's broken!)
- (5 points)
How many cycles are needed to complete execution of a program
with a million instructions if using a pipelined implementation
with five pipeline stages?
If it depends, on what, and what's the maximum and minimum?
(For the maximum, explain how you came up with the number you did;
on reflection I realize that I'd have a tough time being sure about
this myself!)
For programming assignments, this section should go in the body of the e-mail
or in a plain-text file pledge.txt (no word-processor files
please).
For written assignments, please put it in the text or PDF file with
your answers.
Include the Honor Code pledge or just the word “pledged”,
plus at least one of the following about
collaboration and help (as many as apply).
Text in italics is explanatory or something for you to
fill in.
- I did not get outside help aside from course
materials, including starter code,
readings, sample programs, the instructor.
- I worked with names of other students on this
assignment.
- I got help with this assignment from
source of help -- ACM
tutoring, another student in the course, etc.
(Here, “help” means significant help,
beyond a little assistance with tools or compiler errors.)
- I got help from outside source --
a book other than the textbook (give title and author),
a Web site (give its URL), etc..
(Here too, you only need to mention significant help --
you don't need to tell me that you
looked up an error message on the Web, but if you found
an algorithm or a code sketch, tell me about that.)
- I provided help to names of students on this
assignment.
(And here too, you only need to tell me about
significant help.)
For programming assignments, this section should go in the body of the e-mail
or in a plain-text file pledge.txt (no word-processor files
please).
For written assignments, please put it in the text or PDF file with
your answers.
Include a brief essay (a sentence or two is fine, though you can write
as much as you like) telling me what if anything you think
you learned from the assignment, and what if anything you found
interesting, difficult, or otherwise noteworthy.
2021-05-12