21a. Draw the state graph and corresponding transition table fora 3-bit counter with no control inputs that counts in multiples of3. That is, the count sequence is: 000-011-110-000-.... Use don'tcares in the transition table as appropriate.
b. Draw the state graph and corresponding transition table for a3-bit binary counter with no control inputs which counts downrather than up. Include a Z output which signifies when the \"countvalue modulo 3 is equal to 0.\"
c. Draw the state graph for a 3-bit up/down counter which hasthe following inputs: CLR, INC, DEC. Make it so the inputs havepriority in that order. Add a Z output which signifies whenever thecurrent state of the counter is either '010' or '110'.
