This device contains two independent negative-edge-triggered J-K flip-flops with complementary outputs. The J and K data is processed by the flip-flop on the falling edge of the clock pulse. The clock triggering occurs at a voltage level and is not directly related to the transition time of the falling edge of the clock pulse. Data on the J and K inputs may be changed while the clock is HIGH or LOW without affecting the outputs as long as the setup and hold times are not violated.
A low logic level on the preset or clear inputs will set or reset the outputs regardless of the logic levels of the other inputs.