|  | // Copyright (C) 2020-2021  The SymbiFlow Authors. | 
|  | // | 
|  | // Use of this source code is governed by a ISC-style | 
|  | // license that can be found in the LICENSE file or at | 
|  | // https://opensource.org/licenses/ISC | 
|  | // | 
|  | // SPDX-License-Identifier:ISC | 
|  |  | 
|  | (* blackbox *) | 
|  | module box( | 
|  | (* invertible_pin="INV_A" *) | 
|  | input  wire A, | 
|  | input  wire B, | 
|  |  | 
|  | output wire Y | 
|  | ); | 
|  |  | 
|  | parameter [0:0] INV_A = 1'b0; | 
|  |  | 
|  | endmodule | 
|  |  | 
|  |  | 
|  | module top( | 
|  | input  wire [1:0] di, | 
|  | output wire [5:0] do | 
|  | ); | 
|  |  | 
|  | wire [1:0] d; | 
|  |  | 
|  | \$_NOT_ n0 (.A(di[0]), .Y(d[0])); | 
|  |  | 
|  | box b00 (.A(d[0]), .B(    ), .Y(do[0])); | 
|  | box b01 (.A(d[0]), .B(    ), .Y(do[1])); | 
|  | box b02 (.A(    ), .B(d[0]), .Y(do[2])); | 
|  |  | 
|  | \$_NOT_ n1 (.A(di[1]), .Y(d[1])); | 
|  |  | 
|  | box b10 (.A(d[1]), .B(    ), .Y(do[3])); | 
|  | box b11 (.A(d[1]), .B(    ), .Y(do[4])); | 
|  | box b12 (.A(d[1]), .B(    ), .Y(do[5])); | 
|  |  | 
|  | endmodule |