In: Electrical Engineering
21a. Draw the state graph and corresponding transition table for a 3-bit counter with no control inputs that counts in multiples of 3. That is, the count sequence is: 000-011-110-000-.... Use don't cares in the transition table as appropriate.
b. Draw the state graph and corresponding transition table for a 3-bit binary counter with no control inputs which counts down rather than up. Include a Z output which signifies when the "count value modulo 3 is equal to 0."
c. Draw the state graph for a 3-bit up/down counter which has the following inputs: CLR, INC, DEC. Make it so the inputs have priority in that order. Add a Z output which signifies whenever the current state of the counter is either '010' or '110'.