1. Draw and asynchronous state machine for a 5 input combination lock.

A. Each single bit input corresponds to a number (pushbutton). When pushed, the corresponding bit goes high, when release, it goes low.

B. One other input, for the handle, goes high when the person tries the handle and goes low when released.

C. The system should reset when the handle is released.

D. The only output is an "open" signal that is high when the three digit (pre-programmed) combination is entered correctly. Open goes low after reset.

knowing that it is asynchronous what might you do to try to break into a room secured by this lock?

 

2. Draw the synchronous and asynchronous versions of the D-FF state machine.