A sequential circuit has four state registers or flipflops a

A sequential circuit has four state registers (or flip-flops) and 2 inputs

(a) How many states does it have? List them (Use 0s & 1s)

(b) How many transitions from each state does it have? List them (Use 0s & 1s)

(c) How many total transitions does it have?

Solution

(a) As there are four flip-flops used, so there are 2^4 =16 states are present. They are

0000,0001,0010,0011,0100,0101,0110,0111,1000,1001,1010,1011,1100,1101,1110,1111

(b)Each state will have four transitions as there are two inputs (2^2=4)

Let x and y be inputs then

00,01,10,11 will be transitions from one state to its respective other state

(c) As there are 4 flipflops and two inputs, so total number of transitions will be 2^(4+2)=2^6=64

000000 to 111111