CSCI 162 Spring 2018: Circuit Lab: A Simple Circuit


For this lab, you will use the Logic Gate Simulator available from the Applications menu → Education → Logisim. In this lab, we will design and implement (in a web simulator) a circuit that computes the function that takes four inputs, x0, x1, x2, and x3, and evaluates to TRUE (on) if an even number of the inputs are TRUE, and FALSE if an odd number of the inputs are TRUE.
  1. Construct the Truth Table for the boolean function.
  2. Design the circuit just out of AND, OR and NOT gates that will compute x0 XOR x1. Check that it is correct by testing it on all possible inputs. Label this output "odd x0, x1"
  3. Replicate it for computing x2 XOR x3. Test on a few inputs. Label it "odd x2, x3".
  4. Construct the equivalent for "even x0, x1" and "even x2, x3". Consider how to do so while "reusing" the circuits you already have available on the board.
  5. Combine the outputs to form "even" and "odd". Note that "even" = ("even x0, x1" AND "even x2, x3") OR ("odd x0, x1" AND "odd x2,x3").
  6. Test this circuit on the 16 possible input combinations, and debug if necessary.