git.rot13.org Git - trilby-hat-fpga/blob - blinky.v

   1 module top(input clk,
   2                 //#input btn,
   3                 output green_led_d7,
   4                 output orange_led_d8,
   5                 output red_led_d5,
   6                 output yellow_led_d6
   7         );
   8     localparam ctr_width = 24;
   9     localparam ctr_max = 2**ctr_width - 1;
  10     reg [ctr_width-1:0] ctr = 0;
  11     reg [9:0] pwm_ctr = 0;
  12     reg dir = 0;
  13         reg btn = 0;
  14
  15     always@(posedge clk) begin
  16     ctr <= dir ? ctr - 1'b1 - btn: ctr + 1'b1 + btn;
  17         if (ctr[ctr_width-1 : ctr_width-3] == 0 && dir == 1)
  18             dir <= 1'b0;
  19         else if (ctr[ctr_width-1 : ctr_width-3] == 7 && dir == 0)
  20             dir <= 1'b1;
  21         pwm_ctr <= pwm_ctr + 1'b1;
  22     end
  23
  24     reg [9:0] brightness [0:7];
  25     localparam bright_max = 2**10 - 1;
  26     reg [7:0] led_reg;
  27
  28     genvar i;
  29     generate
  30     for (i = 0; i < 8; i=i+1) begin
  31        always @ (posedge clk) begin
  32             if (ctr[ctr_width-1 : ctr_width-3] == i)
  33                 brightness[i] <= bright_max;
  34             else if (ctr[ctr_width-1 : ctr_width-3] == (i - 1))
  35                 brightness[i] <= ctr[ctr_width-4:ctr_width-13];
  36              else if (ctr[ctr_width-1 : ctr_width-3] == (i + 1))
  37                  brightness[i] <= bright_max - ctr[ctr_width-4:ctr_width-13];
  38             else
  39                 brightness[i] <= 0;
  40             led_reg[i] <= pwm_ctr < brightness[i];
  41        end
  42     end
  43     endgenerate
  44
  45     // assign led = led_reg;
  46         assign green_led_d7  = led_reg[2];
  47         assign red_led_d5    = led_reg[3];
  48         assign yellow_led_d6 = led_reg[4];
  49         assign orange_led_d8 = led_reg[5];
  50
  51 endmodule