JK flip-flop, J = 1, K = 1 — flip-flops
corethe row that makes JK useful
Answer
Q⁺ = 1
Why this example is worth doing
Where SR forbids both inputs asserted, JK defines it as toggle — and that single decision turns the device into a frequency divider and the building block of every ripple counter. The page gives the characteristic equation Q⁺ = J·Q̄ + K̄·Q and shows the toggle row falling out of it, so the behaviour is derived rather than memorised as a special case.
Try your own input in the Flip-flops & latches. SR, D, JK and T: characteristic tables, excitation tables and timing diagrams.
How the answer is reached
The probed row
J = 1, K = 1, Q = 0
Output table
| J | K | Q | Q⁺ |
|---|---|---|---|
| 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 1 |
| 0 | 1 | 0 | 0 |
| 0 | 1 | 1 | 0 |
| 1 | 0 | 0 | 1 |
| 1 | 0 | 1 | 1 |
| 1 | 1 | 0 | 1 |
| 1 | 1 | 1 | 0 |