2. Flip_Flops  Logic circuits are classified ito two groups  1. The combinational logic circuits,using the basic gates AND,OR and NOT.  2. Sequential logic circuits involving timing and memory devices.  The basic building block of the combinational logic circuits is the logic gates. The basic building block for sequential is the flip_flops

3. Logic ciorcuit for J-K FF

5. J-K Flip flop

7. The R-S Flip_flop using 2-OR gates

8. R-S Flip_flop using NOR Gate

9. The R-S Flip flop using NAND Gate

10. The truth table for R-S Flip- flop Q’QRS Previous state 00 0101 1010 Prohibited state 11

11. The truth table for R-S flip_flop Effect on output Q Q’QRSMode of operation Prohibited_ Do not use 1100Prohibited For setting Q to 1 0110Set For resetting Q to 0 1001Reset Depends on previous state Q’Q11Hold

12. The clocked R-S Flip flop

13. The clocked RS Flip-flop

14. The clocked RS using AND and NOT logic gates

15. The clocked RS using NAND and AND gates

16. The T-FF

17. The logic symbol for the T_FF

18. The D- Flip-flop

19. The clocked RS-FF using NAND gates

20. The truth table for the clocked RS-FF Q’QRSCLK Previous state 001 01011 10101 Prohibited state 111 01011 01100