|  | // 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 | 
|  |  |