4-bit counter

Hey, I'm new to electronics, and for one of my projects, I'm supposed to design an Ultrasonic Rangefinder using Analog components only! The components include the 555 timers, SN74HC chips (specifically the 4 bit counter), 7 segment display and etc. Most of the guides I have found online use an...

Hi, I'm a beginner for the digital circuit. Recently I encounter a problem when trying to implement a 4-bit counter by using Quartus. Following are my diagram and simulation outcome, the problem is why the simulation is not correct? I hope someone can help me, thanks! Diagram Simulation