Lab Assignment

The objective of this lab is to practice your Verilog coding and the design of a Finite State Machine.

Lab Goal:

For this lab, you will code a Verilog module to implement the FSM described in this document. This lab will also require that you use the Seven-Segment Display on the DE0-CV FPGA board.

Design Specifications for the FSM

Implement the following simple state machine on the DE0-CV FPGA board. This FSM will have 5 states. The clock to this FSM will be provided by yourself using KEY0 (one of the push buttons on the board). It is highly recommended that you use a debounce module (to be covered in class) to ensure that spurious clocks do not occur when using a push-button to emulate a clock.

The transitions from any one state to another are determined by switches 0 through 4 of the board (SW0, SW1, SW2, SW3, and SW4) as shown in the state diagram below. This will be easier than using pushbuttons for the inputs to switch to states. That means you set the switch and then clock using KEY0. It really only matters what the switches are doing when the clocking occurs.

NOTE reiterating this use Switches instead of pushbuttons for input. Use KEY0 for clock.

Any input transition not explicitly referenced in the diagram keeps the machine in the same state. Moreover, if two or more switches are asserted simultaneously, no transition should occur. In other words, the switches are to be treated as one-hot and your design should enforce this provision. The only exception to this is SW0 which acts as the reset and should reset the FSM to S_00 regardless of all other switches or the pushbutton. (note you could use KEY1 pushbutton instead but it isn't clear that would be better).

Required use of the 4-digit, 7-segment display

The 7-segment display should be used to indicate which state the FSM is in. For S_01, S_02, S_03, and S_04 the 4-digit display should display exactly that: S_01, S_02, S_03, or S_04. The one exception is that whenever the machine is in S_00, the 4-digit, 7-segment display should display the first four digits of your last name using the table below.

There is an onboard oscillator (50 MHz). Do not use the clock to clock the FSM, use KEY0, the FSM cannot work from the internal clock because you have to change input between clocks. Pin configurations can be found in section 3.4 of the DE0-CV manual. For information on how to use 7-segment display, refer to the section 3.3 in the manual.

Required use of LEDs

Whenever any of the switches (SW0, SW1, SW2, SW3, and SW4) are in the ON position, the corresponding LED (LEDR0, LEDR1, LEDR2, LEDR3, and LEDR4) should be ON.

Submission of Completed Lab:

Please upload the following files to the Lab3 Submission link on Blackboard:

• All Verilog source files (including testbech, and submodules)
• Board programming file (lab3.sof file which can be found in output files directory)
• A lab report in PDF format, include following in the report:

o Waveform simulations covering all transitions and proving the full functionality.
o Brief explanations of the design and organization of your code (Code snippets can be helpful in your explanations)
o Brief explanation of the tests you performed in your testbench

• You can use the following test sequence: SW0 - 10000000000000000

SW1 - 00111010010101000
SW2 - 00000000001000010
SW3 - 00000001100000100
SW4 - 00000100000010001.