Overview

This Exercise is based on the material covered in Real Digital Project 10, which can be found in the red tab to the right. A downloadable document for this exercise is available in the orange tab to the right. The mention of grading within the downloadable document is due to the exercise material being used as course work for an electrical engineering class at a university.

Problem 1.

Assign state codes to the state diagrams below, and discuss the motivation behind your choice of state codes.

Problem 2.

Modify the state diagram branching conditions in the diagrams below as needed to ensure the sum and exclusion rules are obeyed in each case. You can add a holding conditions or change branch codes as desired.

Problem 3.

A vending machine should SELL an item if 30 cents is input. The machine has a coin sensor that can detect nickels, dimes, and quarters, and reject everything else. No change is given (i.e, if two quarters are input, simply assert SELL and keep the fifty cents).

Create a state diagram for a machine that can control a 4-button digital combination lock mechanism, unlocking only if the sequence B0-B3-B1 is detected.

Problem 4.

Sketch circuits for the state machines below.