An-Najah National University
Department of Computer Engineering
Digital Circuits Design
Assignment # 2
Using Multisim Workbench, design the following circuit, individually:
Treasury of Valuables
Design a sequential circuit with 4 inputs and 3 outputs, as in the figure.
This system is used as digital lock for a treasury of valuables. To open the
treasury, the user must enter a serial binary password of 4 bits. Each bit is
entered with a manual pulse at the input CLOCK. If the entered password is
correct, the output LOCK is logic 1 and the treasury is open (you may use a
green light to indicate the action). The treasury will remain open as long as
the password is correct, but if the user enters an incorrect password, then the
treasury will close. Don’t forget the pulse to enter the data!
While if the entered password is wrong, then the output ALARM is logic 1
(informing the police) and LOCK is logic 0 (the treasury is not open). You
may use an orange light to indicate the police and red light to indicate that the
treasury is not open.
The user can change the password by pressing input PR, but he/she must enter
the old password, followed by the 4-bit new password (8 bits total). If the
user enters the correct old password and a 4-bit new password, the output
PCh will be logic 1. The user has 2 wrong attempts to change the password,
otherwise the output ALARM will become 1.
If the output ALARM is logic 1, it would never become 0 until the user press
the input RESET followed by the correct password.
Note: the starting password is 0000
Deadline: Saturday 22/05/2021
Good Luck