8bitworkshop/presets/verilog/switches.v

`include "hvsync_generator.v"

/*
Switch test program.

Player 1 Keys: arrow keys + space + shift
Player 2 Keys: A/D/W/S + Z + X
*/
module switches_top(clk, reset, hsync, vsync, 
                    switches_p1, switches_p2,
                    rgb);

  input clk, reset;
  input [7:0] switches_p1;
  input [7:0] switches_p2;
  output hsync, vsync;
  output [2:0] rgb;
  wire display_on;
  wire [8:0] hpos;
  wire [8:0] vpos;
  
  hvsync_generator hvsync_gen(
    .clk(clk),
    .reset(reset),
    .hsync(hsync),
    .vsync(vsync),
    .display_on(display_on),
    .hpos(hpos),
    .vpos(vpos)
  );
  
  // select p1 bit based on vertical position
  wire p1gfx = switches_p1[vpos[7:5]];
  // select p2 bit based on horizontal position
  wire p2gfx = switches_p2[hpos[7:5]];

  assign rgb = {1'b0, 
                display_on && p1gfx,
                display_on && p2gfx};

endmodule