Design a sequential logic circuit that will act as a decimal countdown counter using a number of 7-segment displays beside some input device for initializing the count of each counter. The user sets up the decimal count for each digit manually by pressing the one of the setup buttons (number of buttons is a design task). The counter starts counting down in decimal until it reaches zero. When done this action opens lock (simulated by a LED).

Design Requirements

The design should work as well as a Lock Opener. Therefore, when the user enters a secret digit decimal key the lock opens (the number of keys left as a design task) This will utilized by the load action to a register

The circuit must have some input control line X1, X2, etc., similar to the number of counters, acting as switches that triggers the counters for loading initial digits. Therefore, when a switch in pressed, corresponding 4-bit counter will add up by one until it reaches the required digit, then we may proceed to the next counter.

For the Lock Opener, the PIN is saved as a hardwired pattern for a comparator component to work on (see EXOR gates and how it works as a comparator) that compares the 4 4-bit key with the 4 counter outputs.

The 7- segment display (common enable) is directly linked to the counters and it always shows what the counters is currently holding.

Simulation Software

Use it to embed all the project circuit.

oThe student is required to use IO capability of the package to simulate switches opening and closing operations (needed to increment or decrement all counters). Also LEDs should be connected to states storage cells.

template:

6 lines description of the project?

Name of the simulation package used with Version?

Outline the steps taken to design your decade count down counter

State Diagram?

State Table?

Excitation Tables?

Next state Table?

K-Maps minimization for all Flip-Flops inputs?

Circuit Diagram for the decade counter?

List of all components used with quantity?

Component	Description	Quantity

Partial Drawings for all sections (one by one with names mentioned). (Cut from LogiSim then paste as image).

Clock Section

Four Counters Section

Input Section (Switches, etc.)

Output Section

Comparator Section

Any Control section

10 lines on description of how it works?

Snapshots of:

Loading initial content for every counter?

The 4 counters counting UP all together?

How data is loaded and lock opens (LED)?

Components count weights?

Fill next table?

Number of Total components
Number of connection lines used