In reply to dave_59:
Thanks dave. To follow your answer.
In the following example i have define `timescale compiler directive in adice.v and compiled and elaborated both adice.v and file2.v together as single compilation unit.
The timescale of file2.v is 1ps/1ps?
file - adice.v
`timescale 1ps/1ps
module adice;
int i, j
file2 file2(.i(i), .j(j));
endmodule
file - file2.v
module file2(input i, output o);
initial $printtimescale
endmodule