The RS flip-flop is a simple latch with reset 'R' and set 'S' inputs.
The RS flip-flop may have an enable pin. If the enable pin is present and inactive then the output pin is not set and can be treated as if disconnected from the circuit.
Truth table:
| S | R | Q |
|---|---|---|
| 0 | 0 | unchanged |
| 0 | 1 | 0 |
| 1 | 0 | 1 |
| 1 | 1 | undefined |