File talk:JK flip-flop NAND.svg

This is not actually a flip-flop

If J and K are both 1, the expected behavior for a JK flip-flop is that it will make a single transition, flipping state, at the clock. To be able to do that requires some way of isolating the outputs from the inputs to avoid a feedback loop. The two ways to do this are with a 6-gate edge-triggered circuit that uses a race to disable the clock and an 8-gate master/slave configuration that uses two separately gated latches.

This circuit is basically a 4-gate gated SR latch not a flip-flop. It does not have isolated inputs and outputs. If J and K are both 1 and the clock is held high for more than 2 gate delays, both outputs will go to 1. From there, it's indeterminate how it will settle when the clock goes to 0. This circuit only works if the clock is a spike, its width carefully set to be between 1 and 2 gate delays wide, not a realistic design point. Msnicki (talk) 19:47, 3 December 2016 (UTC)