I have been trying to build a circuit to incorporate 3x D FFs as part of asynchronous up-counter followed by logic that will allow me to create a 4 bit arbitrary sequence: 0, 1, 3, 7, 15, 12, 8. My current design comes up an error on the graph tool saying that I still need to connect a logic probe even though there seems to be one in place at one of the outputs I'm currently trying to check. I'd like to be able to insert D FFs to provide up-counter inputs to the logic circuit draft design but can't find a tool allowing me to do this. Any assistance would be much appreciated.
