Four types of flip-flops are commonly considered: JK, SR, D and T a Each store binary data but have a unique set of input variables a each flip-flop can be described in terms f input and output characteristics by writing special truth table called an excitation table A characteristics equation can be generated from the excitation tables◼ Four types of flip-flops are commonly considered: JK, SR, D and T. ◼ Each store binary data but have a unique set of input variables. ◼ Each flip-flop can be described in terms of input and output characteristics by writing special truth table ,called an excitation table. ◼ A characteristics equation can be generated from the excitation tables