pwm_generator.v

// AstroTinker Bot : Task 1A : PWM Generator
/*
Instructions
-------------------
Students are not allowed to make any changes in the Module declaration.
This file is used to design a module which will scale down the 3.125MHz Clock Frequency to 195.125KHz and perform Pulse Width Modulation on it.

Recommended Quartus Version : 20.1
The submitted project file must be 20.1 compatible as the evaluation will be done on Quartus Prime Lite 20.1.

Warning: The error due to compatibility will not be entertained.
-------------------
*/

//PWM Generator
//Inputs : clk_3125KHz, duty_cycle
//Output : clk_195KHz, pwm_signal


module pwm_generator(
    input clk_3125KHz,
    input [3:0] duty_cycle,
    output reg clk_195KHz, pwm_signal
);

initial begin
    clk_195KHz = 0; pwm_signal = 1;
end

//////////////////DO NOT MAKE ANY CHANGES ABOVE THIS LINE//////////////////

reg [2:0] counter = 0; // counts 0 to 7
reg [4:0]pwd_count=0;

always @ (posedge clk_3125KHz) begin
    if (!counter) clk_195KHz = ~clk_195KHz; // toggles clock signal
    counter = counter + 1'b1; // increment counter // after 7 it resets to 0
end


always @ (posedge clk_3125KHz) begin
	pwd_count=pwd_count+1'b1;
	if (pwd_count==16)begin
		pwd_count=0;
	end
	if ((pwd_count > 0)&(pwd_count <= duty_cycle)) begin
		pwm_signal = 1'b1;
	end
	else
		pwm_signal = 1'b0;	
end
	


//////////////////DO NOT MAKE ANY CHANGES BELOW THIS LINE//////////////////

endmodule