30. PWM with 4-bit Resolution

How do you plan to solve it?

module pwm4_basic(
   input clk,
   input rst,
   input [3:0]duty,
   output reg pwm_out
);
   reg [3:0]counter;

always @ (posedge clk)
begin
    if(rst)begin
        pwm_out <= 0;
        counter <= 4'b0000;
    end 
    else
    begin
      counter <= counter+1;
      if(counter<duty)
         pwm_out <= 1;
      else
         pwm_out <= 0;
      end 
    end


endmodule