We know that the basic gated SR latch suffers from two basic problems: number one, the S = 0 and R = 0 condition or S = R = 0 must always be avoided, and number two, if S or R change state while both Q and Q’ are low the correct latching action may not occur. Then to overcome these two fundamental design problems with the SR latch, the JK flip-Flop was developed. This simple JK flip-Flop is the most widely used of all the flip-flop designs and is considered to be a universal flip-flop circuit. The sequential operation of the JK flip-flop is exactly the same as for the previous SR flip-flop with the same "Set" and "Reset" inputs. The difference this time is that the JK flip-flop has no invalid or forbidden input states of the SR Latch (when S and R are both 1).