InterruptConverter

module InterruptConverter (/*AUTOARG*/
   // Outputs
   edge_irq,
   // Inputs
   clk, level_irq
   ) ;
   input clk;

   input level_irq;
   output reg edge_irq;

   reg   [3:0] shift_register = 0;

   always @ ( posedge clk ) begin
      shift_register <= { shift_register[2:0], level_irq };

      if (shift_register == 4'b1100) begin
         edge_irq <= 1;
      end else begin
         edge_irq <= 0;
      end
   end

endmodule // InterruptConverter