CLOCKED R-S FLIP-FLOP
These flip-flops are derived from the R-S flip-flop only added with a clock function (as a clock).
Here is the logic symbol for the ticking R-S flip-flop:
Figure 1 R-S flip-flop logic symbol ticking
Figure 2 R-S flip-flop circuit ticking using NAND
From this flip-flop what must be remembered is that the output of the R-S flip-flop will change when there is one clock pulse. This R-S flip-flop if once set or reset will remain in that state unless we change some inputs. This is a characteristic of memory.
The truth table of the R-S flip-flop ticks:
Figure 3 Waveform diagram of a ticking R-S flip-flop
Figure 4 R-S flip-flop ticking problem