By feeding the output from the sequential logic back into the input of the LUT, a new type of device is created: the Finite State Machine (FSM).
In some systems it might be necessary to use feedback to achieve the desired functionality. Knowing the output state of the system can be very useful, so internal feedback from the sequential logic output is possible to any of the inputs on both LUTs, making the feedback system very flexible.
Figure 1. Internal Feedback
