In: Electrical Engineering
Objective: Design, construct, and test a three-bit counter that counts up or down. An enable input E determines whether the counter is on or off.
If E=0, the counter is disabled and remains at its present count even though clock pulses are applied to the flip-flops.
If E=1, the counter is enabled and a second input, x, determines the direction of the count.
If x=1, the circuit counts upward with the sequence 000, 001, 010, 011, 100, 101, 110, 111 and the count repeats.
If x=0, the circuit counts downward with the sequence 111, 110, 101, 100, 011, 010, 001, 000 and the count repeats. (Do not use E to disable the Clock) Note: Design the sequential circuit with E and x as inputs.