
interface my_interface(
  input clock,
  input select,
  input [3:0] data);
  
  clocking cb @(posedge clock);
    input select, data;
  endclocking
endinterface
 

module top () ;
timeunit 100ps;
timeprecision 1ps;
endmodule

 
module bottom1 () ;
timeunit 10ps;
timeprecision 1ps;
endmodule

module bottom2 () ;
 
 
endmodule


module middle ();
  timeunit 10ps;
  timeprecision 1ps;
  wire a, b, c;
  module nested;
    assign c = a & b;
  endmodule
endmodule


`timescale 100ps/10ps


module bottom3 () ;
endmodule