107 lines
3.2 KiB
Verilog
107 lines
3.2 KiB
Verilog
/*
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* Copyright (c) 2005 Stephen Williams (steve@icarus.com)
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*
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* This source code is free software; you can redistribute it
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* and/or modify it in source code form under the terms of the GNU
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* General Public License as published by the Free Software
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* Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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*/
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/* $Id: real8.v,v 1.1 2005/07/07 16:26:05 stevewilliams Exp $ */
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/*
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* This test demonstrates (and checks) the handling of real values and
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* expressions in some ways that baseline IEEE1364-2001. Particularly,
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* reg and wire values with types, and nets able to carry real values
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* through delays.
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*/
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module main;
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// This is *not* valid baseline Verilog, but iverilog extensions
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// support this. These statements declare a real valued variable
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// and a real valued net.
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reg real target;
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wire real feedback;
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// The feedback should take the target value 10 time units
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// after any change in the target value.
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assign #(10) feedback = target;
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// The control value is calculated from the current target
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// and feedback values. This is recalculated whenever either
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// of the inputs change.
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wire real control = (feedback - target)/2.0;
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initial begin
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target = 16.0;
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// The target should, after this assignment, have a well
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// defined value 16, but the feedback should remain at NaN
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// for a while.
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#1 $display($time,,"target=%f, feedback=%f, control=%f",
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target, feedback, control);
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if (target != 16.0) begin
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$display("FAILED -- target value is not correct.");
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$finish;
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end
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// feedback is still undefined.
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// By now, the feedback as taken on a value, and the control
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// should have been calcluated.
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#10 $display($time,,"target=%f, feedback=%f, control=%f",
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target, feedback, control);
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if (feedback != 16.0) begin
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$display("FAILED -- feedback has wrong value.");
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$finish;
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end
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if (control != 0.0) begin
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$display("FAILED -- control has wrong value.");
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$finish;
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end
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target = 8.0;
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#9 $display($time,,"target=%f, feedback=%f, control=%f",
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target, feedback, control);
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if (feedback != 16.0) begin
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$display("FAILED -- feedback has wrong value.");
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$finish;
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end
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if (control != 4.0) begin
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$display("FAILED -- control has wrong value.");
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$finish;
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end
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#2 $display($time,,"target=%f, feedback=%f, control=%f",
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target, feedback, control);
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if (feedback != 8.0) begin
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$display("FAILED -- feedback has wrong value.");
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$finish;
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end
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if (control != 0.0) begin
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$display("FAILED -- control has wrong value.");
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$finish;
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end
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$display("PASSED");
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$finish;
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end
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endmodule // main
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