An SR latch with the addition of an enable signal. The top signal is R (Reset), the middle signal is E (Enable), and the bottom signal is S (Set). Enable must be ON when you set S or R or else it won't change.
The top LED indicates the SET condition and the bottom LED indicates the RESET condition .
If both S and R are set while E is enabled it enters an invalid state since it can't be set AND reset at the same time.
