Overview

Written work: Problems 1-11.2, 11.4-1.5, & 11.7-11.8

Complete problems covering topics from Chapter 2 (use either document format; Clearly show work; Typed work is preferred):

Problem 11

Consider a 2-to-1 multiplexor with four inputs:

  • i0: Input 0
  • i1: Input 1
  • s: The selector
  • en: The active low “enable”. And one output:
  • out: Should be 0 if enable is 1. Otherwise it is based on the selector and i0’s value when s is 0 and i1’s value when s is 1.

Caution!

Complete the problem as-written. However, there was an unintentional typo.

  • Usually a signal like en would be active when high (1). That is, the normal convention would be for the output to be disabled when en is 0 and enabled when en is 1.
  • Or if the behavior described was what was really intended, the signal would likely have been named nEn, for not enable (rather than en), to indicate that a 1 would not-enable (disable) it.

11.1

Complete the full truth table for this multiplexor.

11.2

Find the full, canonical sum-of-products equation for it.

11.3

Download and work in this JLS starter: hw2b_11p3.jls. Implement the full combinational logic circuit for the circuit. For non-binary expressions (like a 3-way or more and) use mult-bit input gates.

11.4

What is the Propagation delay in JLS (using default delays)? (You can right-click on gates and select Change Timing to examine their default timing values, but do not change them).

11.5

Give the minimized (the Karnaugh Map sense) Boolean equation for the function.

11.6

Download and work in this JLS starter: hw2b_11p6.jls. Implement the combinational logic for the minimized version.

11.7

What is the Propagation delay in JLS (using default delays) of the minimized circuit?

11.8

Compare and contrast the two minimal version with the default version.

Submission

You will need to submit your assignment via Gradescope. Part of the submission process will require you to indicate where your work is for each individual problem. Please:

There are three distinct Gradescope assignments listed: one for all written questions and one for each of the two JLS circuits.

JLS problems are unit tested for the grade. When you submit to Gradescope the test cases will be run and results should be available within a few minutes. You can stay on the submission page to see the resutls or come back to it later. Usually you can review details of each passed or failed test case and, if needed, try to recreate it in JLS for additional testing. You can review the results to try to fix any errors and resubmit.

Caution!

These problems are precisely defined. The autograder checks for the expected timing (when the JLS simulation completes) as well as the behavior (the correct outputs for given inputs).