Question

9) Please answer full question thoroughly (including subsets) showing detailed work. Double check answer and work to ensure it is correct for thumbs up.

A) Think about the stoplights you have seen. In this case, we are designing a simple four-way stoplight with the values shown in the first two columns of the truth table. it is your job using what you know about digital logic (and the meanings of the ones and zeros, using the positive logic convention) to fill out the remainder of the truth table with ones and zeros.

LIGHTS CLOCK INPUT BITS LIGHT 1 LIGHT 2 co G YRG YR 1 / 2 C2 C1 co 0 1 10 | 11

B) Draw the Karnaugh maps for your logical truth table on a separate sheet of paper. These will help you derive the minimal circuit in terms of gates. Attach your K-maps, and write your final expressions here for each of the six outputs. While it is possible to reduce all six equations down to a total of nine two input gates (plus inverters), it is not necessary as you will not implement your design with discrete logic chips. It is completely optional, although it may simplify your schematic if you can do it.

i) G1 =

ii) Y1 =

iii) R1 =

iv) G2 =

v) Y2 =

vi) R2 =

C) Draw the resulting circuit(s) on a separate sheet of paper. If you see any combinations you can make to reduce the number of gates while maintaining functionality, you may do so now. Attach your circuit diagram.