1
ESP1104 Introduction to Electronic Systems
Tutorial 8
1) Consider the following truth table. A, B, and C represent the inputs, F to K represent the outputs. Write Boolean expressions for the outputs.
A B C F G H I J K 0 0 0 1 1 1 0 0 1 0 0 1 0 0 1 0 1 1 0 1 0 1 0 1 0 0 0 0 1 1 0 1 0 1 1 0 1 0 0 0 0 1 0 0 0 1 0 1 1 0 1 0 1 0 1 1 0 0 0 1 1 1 1 1 1 1 1 0 1 1 1 1
2) Use only NAND gates to implement the XOR function for two inputs. And then use only NOR gates to implement the XOR function for two inputs.
3) A city council has three members, A, B, and C. Each member votes on a proposition (1 for yes, 0 for no). Find a minimized logic expression having inputs A, B, and C and output X that is high when the majority vote is yes and low otherwise.
4) In one particular car, a buzzer sounds whenever the ignition key is turned but a door is open and a seat belt is not fastened. The buzzer also sounds when the key is not turned but the lights are on. In addition, the car will not start unless the key is the ignition, the car is in park, and all doors are closed and seat belts fastened. Design a logic circuit that takes all the inputs listed and sounds the buzzer and starts the car when appropriate.
5) Design a logic circuit that gives an output X that is high when an error in the form of an unused code occurs in a given BCD code 4-bit word. Suppose the input BCD codeword is B8B4B2B1.
6) Design a logic circuit that takes a 4-bit Gray code inputs and determine if the input value is a multiple of 3.
