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//

// pixel.v -- last stage in display pipeline

//

module pixel(clk, pixclk, attcode,

             pixel, blank, hsync_in, vsync_in, blink,

             hsync, vsync, r, g, b);

    input clk;

    input pixclk;

    input [7:0] attcode;

    input pixel;

    input blank;

    input hsync_in;

    input vsync_in;

    input blink;

    output reg hsync;

    output reg vsync;

    output reg [2:0] r;

    output reg [2:0] g;

    output reg [2:0] b;

  wire blink_bit;

  wire bg_red;

  wire bg_green;

  wire bg_blue;

  wire inten_bit;

  wire fg_red;

  wire fg_green;

  wire fg_blue;

  wire foreground;

  wire intensify;

  wire red;

  wire green;

  wire blue;

  assign blink_bit = attcode[7];

  assign bg_red = attcode[6];

  assign bg_green = attcode[5];

  assign bg_blue = attcode[4];

  assign inten_bit = attcode[3];

  assign fg_red = attcode[2];

  assign fg_green = attcode[1];

  assign fg_blue = attcode[0];

  assign foreground = pixel & ~(blink_bit & blink);

  assign intensify = foreground & inten_bit;

  assign red = (foreground ? fg_red : bg_red);

  assign green = (foreground ? fg_green : bg_green);

  assign blue = (foreground ? fg_blue : bg_blue);

  always @(posedge clk) begin

    if (pixclk == 1) begin

      hsync <= hsync_in;

      vsync <= vsync_in;

      r[2] <= blank & red;

      r[1] <= blank & intensify;

      r[0] <= blank & red & intensify;

      g[2] <= blank & green;

      g[1] <= blank & intensify;

      g[0] <= blank & green & intensify;

      b[2] <= blank & blue;

      b[1] <= blank & intensify;

      b[0] <= blank & blue & intensify;

    end

  end

endmodule