verilog/rtl/pwm_standard_mode.v

`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company: 
// Engineer: 
// 
// Create Date: 09/10/2021 11:02:16 AM
// Design Name: 
// Module Name: standard_mode
// Project Name: 
// Target Devices: 
// Tool Versions: 
// Description: 
// 
// Dependencies: 
// 
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
// 
//////////////////////////////////////////////////////////////////////////////////


module pwm_standard_mode #(
  parameter Resolution = 16
) (
  input                        clk_i,
  input                        rst_ni,
  input       [Resolution-1:0] threshold_counter,
  input       [Resolution-1:0] period_counter,
  input       [Resolution-1:0] step,
  output                       pwm_signal
);

  reg                    output_reg;
  reg   [Resolution-1:0] counter;
  
  assign pwm_signal = output_reg;
  
  always @(posedge clk_i) begin
    if (rst_ni == 0  | threshold_counter == 0) begin
      counter      <= 0;
      output_reg   <= 0;
    end else begin
      if (counter < threshold_counter) begin
        output_reg <= 1;
        counter    <= counter + step;
      end else if (counter >= threshold_counter && counter < period_counter) begin
        output_reg <= 0;
        if (counter >= period_counter - step) begin
            counter <= 0;
        end else begin
            counter <= counter + step;
        end
      end else begin
        output_reg <= 0;
        counter    <= 0;
      end
    end
        
        
  end
    
  
endmodule