CS-343 Assignment 2

Due Date and Submission

This assignment is due by midnight, February 9 Submit it by sending email to me at the address, vickery@babbage.cs.qc.edu. Be sure to put "CS-343 Assignment 2" in the subject of your email and to put your name/ID in the message body.

I prefer it if you put your answers inline in the body of your message instead of as an attachment. And I prefer plain text over HTML or word processor documents.

The Assignment

  1. Computer A is twice as fast as computer B. Computer A takes ten seconds to run a program. How long will computer B take to run the same program?
  2. Computer A is 60% faster than computer B. Computer A takes ten seconds to run a program. How long will computer B take to run the same program?
  3. Computer B is 60% slower than computer A. Computer A takes ten seconds to run a program. How long will computer B take to run the same program?
  4. Computer B is twice as slow as computer A. Computer A takes ten seconds to run a program. How long will computer B take to run the same program?
  5. A particular Instruction Set Architecture (ISA) has four classes of instruction: load/store, fixed-point, floating-point, and branching. Load/store instructions all require 2 clock cycles to execute, fixed-point instructions all execute in one clock cycle, floating-point instructions all require 8 clock cycles to execute, and branch instructions take one clock cycle if the branch is successful and two clock cycles if the branch fails. A program is run on a processor with this ISA and measurements show that 20% of the instructions executed are load/store, 50% are fixed-point, 5% are floating-point, and the remainder are branches. Just 15% of the branches fail. What is the average number of clock cycles per instruction?
  6. For the previous question, the processor operates with a 2 GHz clock, and the program executes 3 million instructions. How long does it take the program to execute?
  7. A 1.5 GHz clock is used to synchronize the inputs to a logic network that has 7 levels. What is the maximum allowable propagation delay per gate?
  8. A logic network has a 5 levels and the gates have a maximum propagation delay of 12 psec. What is the maximum clock rate that can be used to synchronize the inputs to this network?
  9. A computer has 1,024 registers (numbered 0 to 1,023). Arithmetic instructions for this computer hold three register numbers. How many bits are needed to hold the register numbers?
  10. A byte-addressable memory is one that assigns a unique binary number as the address of each byte. How many bits are needed for the addresses of a 1GB (gigabyte) byte-addressable memory?
  11. How many bits are needed for the addresses of a 16MB byte-addressable memory?