Experiments   
 Experiment #7 Sample Feedback Waveform
This is the simulation of the adder with registered feedback. The register stores the result of the adder as Q[3..0]. This sum is then fed back to the adder to be added with the new data value X[3..0] at each positive edge of the clock.

Registered Feedback Waveform


The waveform above simulates the operations:

x = 9;
x = x + 2;
x = 4;
x = x + 11;