| // 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 | 
 |  | 
 | module inpad ( | 
 |     output Q, | 
 |     (* iopad_external_pin *) | 
 |     input  P | 
 | ); | 
 |   assign Q = P; | 
 | endmodule | 
 |  | 
 | module outpad ( | 
 |     (* iopad_external_pin *) | 
 |     output P, | 
 |     input  A | 
 | ); | 
 |   assign P = A; | 
 | endmodule | 
 |  | 
 | module ckpad ( | 
 |     output Q, | 
 |     (* iopad_external_pin *) | 
 |     input  P | 
 | ); | 
 |   assign Q = P; | 
 | endmodule | 
 |  | 
 | module bipad ( | 
 |     input  A, | 
 |     input  EN, | 
 |     output Q, | 
 |     (* iopad_external_pin *) | 
 |     inout  P | 
 | ); | 
 |   assign Q = P; | 
 |   assign P = EN ? A : 1'bz; | 
 | endmodule | 
 |  | 
 |  | 
 | module dff ( | 
 |     output reg Q, | 
 |     input D, | 
 |     (* clkbuf_sink *) | 
 |     input CLK | 
 | ); | 
 |   parameter [0:0] INIT = 1'b0; | 
 |   initial Q = INIT; | 
 |   always @(posedge CLK) Q <= D; | 
 | endmodule | 
 |  |