Reference no: EM132077

Intro:

In this design, you are going to use a chain of flip-flop to implement a shifter register.

Design requirement

When reset button is pressed, LED0 is on while LED1 to LED 7 are off. When reset button is released, the light keeps shifting from LED0 all the way to LED7 and back to LED0 at a frequency of 0.74Hz

Hints

There are different ways to design the system. Two block diagrams of the system that fulfills the need are shown as follows. You are always welcome to come up with your own design.

1. Simple Shift Register 
2. 2- Filp-Flop with Round Shifter

Sample Codes

Here are some sample codes that you can refer to:

Flip-flop with Asynchronous Reset

always@ (posedge(clk), posedge(rst))

begin

    if(rst == 1)

        Q <= 1'b0;   // Q is reset to 0

    else

        Q <= D;

end

1. Flip-flop with Combinational Logic

2. always@ (posedge(clk), posedge(rst))

   begin

       if(rst == 1)

           Q <= 1'b0;   // Q is reset to 0

       else

           Q <= (A & B);

   end

Now that you've completed this project, try these modifications:

1. Will you add two switches to control how fast the LED shfits: Say, if switch[1:0] is 0, LED shift frequency is 0.745Hz; if switch[1:0] is 1, LED shift frequency is 1.49Hz; if switch[1:0] is 2, LED shift frequency is 2.98Hz; if switch[1:0] is 3, LED shift frequency is 5.96Hz.
2. Instead of shifting the light on LEDs, will you create some fancy LED pattern using LEDs and/or seven segment display?