/* * Copyright (c) 2000 Stephen Williams (steve@icarus.com) * * This source code is free software; you can redistribute it * and/or modify it in source code form under the terms of the GNU * General Public License as published by the Free Software * Foundation; either version 2 of the License, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ /* * This program tests that a non-integer delay gets its extra * precision accounted for if the timescale supports it. In this * example, set the units to 1ms, but set the precision so that the * numbers can be given accurate to .1ms. This should cause a delay * of 2.4 and 2.6 to really be different. */ `timescale 1ms / 100us module main; reg err; reg clk; reg out1, out2; realtime time1; realtime time2; real eps; always @(posedge clk) #2.4 begin $display($time,,$realtime, " set out1 == 1"); time1 = $realtime; out1 = 1; end always @(posedge clk) #2.6 begin $display($time,,$realtime, " set out2 == 1"); time2 = $realtime; out2 = 1; end initial begin clk = 0; out1 = 0; out2 = 0; time1 = 0; time2 = 0; err = 0; $timeformat(-3,1,"ms",5); #1 if (out1 !== 0) begin $display("Error -- out1 s/b 0 at time $time but is=%x", out1); err =1 ; end clk = 1; #3 if (out1 !== 1) begin $display("Error -- out1 s/b 1 at time $time but is=%x", out1); err =1 ; end eps = time1 - 3.4; if (eps < 0.0) eps = 0.0 - eps; if (eps > 0.0001) begin $display("Error -- time1 s/b 3.4 but is=%t", time1); err =1 ; end #1 eps = time2 - 3.6; if (eps < 0.0) eps = 0.0 - eps; if (eps > 0.0001) begin $display("Error -- time2 s/b 3.6 but is=%t, ", time2); err =1 ; end // Use a gold file to check this version. end // initial begin endmodule // main