| // Copyright 2020-2022 F4PGA Authors | 
 | // | 
 | // Licensed under the Apache License, Version 2.0 (the "License"); | 
 | // you may not use this file except in compliance with the License. | 
 | // You may obtain a copy of the License at | 
 | // | 
 | //     http://www.apache.org/licenses/LICENSE-2.0 | 
 | // | 
 | // Unless required by applicable law or agreed to in writing, software | 
 | // distributed under the License is distributed on an "AS IS" BASIS, | 
 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | 
 | // See the License for the specific language governing permissions and | 
 | // limitations under the License. | 
 | // | 
 | // SPDX-License-Identifier: Apache-2.0 | 
 |  | 
 | `timescale 1ps/1ps | 
 |  | 
 | `default_nettype none | 
 |  | 
 | module fpga_interconnect(datain, dataout); | 
 |     input  wire datain; | 
 |     output wire dataout; | 
 |  | 
 |     assign dataout = datain; | 
 |  | 
 |     specify | 
 |         (datain => dataout) = 0; | 
 |     endspecify | 
 |  | 
 | endmodule | 
 |  | 
 | module LUT_K #( | 
 |     //The Look-up Table size (number of inputs) | 
 |     // supports 1<=K<=6 | 
 |     parameter K = 5,  | 
 |  | 
 |     //The lut mask.   | 
 |     //Left-most (MSB) bit corresponds to all inputs logic one.  | 
 |     //Defaults to always false. | 
 |     parameter LUT_MASK={2**K{1'b0}}  | 
 | ) ( | 
 |     //input  wire [K-1:0] in, | 
 |     input  wire [5:0] in, | 
 |     output wire out | 
 | ); | 
 |  | 
 |     wire    [63:0]  LUT_MASK_full; | 
 |     assign LUT_MASK_full =  (K == 6) ?  LUT_MASK[63:0] : | 
 |                             (K == 5) ?  {32'b0, LUT_MASK[31:0]} : | 
 |                             (K == 4) ?  {48'b0, LUT_MASK[15:0]} : | 
 |                             (K == 3) ?  {56'b0, LUT_MASK[7:0]} : | 
 |                             (K == 2) ?  {60'b0, LUT_MASK[3:0]} : | 
 |                                         {62'b0, LUT_MASK[1:0]} ; | 
 |      | 
 |     reg     [5:0]   in_full; | 
 |     always @(*) | 
 |         case(K) | 
 |             6:          in_full <= in[5:0]; | 
 |             5:          in_full <= {1'b0, in[4:0]}; | 
 |             4:          in_full <= {2'b0, in[3:0]}; | 
 |             3:          in_full <= {3'b0, in[2:0]}; | 
 |             2:          in_full <= {4'b0, in[1:0]}; | 
 |             1:          in_full <= {5'b0, in[0]}; | 
 |             default:    in_full <= in[5:0]; | 
 |         endcase | 
 |  | 
 |     assign out = LUT_MASK_full[in_full]; | 
 |  | 
 |     specify | 
 |         (in[0] => out) = 0; | 
 |         (in[1] => out) = 0; | 
 |         (in[2] => out) = 0; | 
 |         (in[3] => out) = 0; | 
 |         (in[4] => out) = 0; | 
 |         (in[5] => out) = 0; | 
 |     endspecify     | 
 |  | 
 | endmodule |