108 lines
3.0 KiB
Coq
108 lines
3.0 KiB
Coq
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/*
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* Copyright (c) 2000 Mark Schellhorn <schellho@nortelnetworks.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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/****************************************************************************
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The following code illustrates an apparent bug in the VCS v5.2 simulator.
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The check for whether or not the memory[0] array element was set correctly
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fails; yet the $display statement immediately after the check shows the
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memory[0] element actually has been set correctly.
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I've noted that if the $display and the check are reversed, the $display
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is incorrect but the check passes.
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This appears to be a problem with the simulator's internal scheduler.
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***************************************************************************/
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module bug_test;
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reg [1:0] temp;
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initial begin
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/********** First test. */
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$display("Running first test.\n");
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// Try setting memory array in other module using hierarchical
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// references & concatenation.
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temp = 2'h3;
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top.memory.memory[0] = {2'h0,temp};
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top.memory.memory[0] = {top.memory.memory[0],temp};
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// Check that setting was made correctly
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if (top.memory.memory[0] != {2{temp}}) begin
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$display("ERROR! top.memory.memory[0] failed to get");
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$display("set correctly!");
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end else begin
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$display("PASS! top.memory.memory[0] set correctly.");
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end
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// Display the value that was checked
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$display("top.memory.memory[0] = %h",top.memory.memory[0]);
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/********** Second test. */
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$display("\nRunning second test.\n");
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// Try setting memory array in other module using hierarchical
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// references & concatenation.
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temp = 2'h3;
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top.memory.memory[1] = {2'h0,temp};
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top.memory.memory[1] = {top.memory.memory[1],temp};
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// Display the value that will be checked
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$display("top.memory.memory[1] = %h",top.memory.memory[1]);
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// Check that setting was made correctly
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if (top.memory.memory[1] != {2{temp}}) begin
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$display("ERROR! top.memory.memory[1] failed to get");
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$display("set correctly!");
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end else begin
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$display("PASS! top.memory.memory[1] set correctly.");
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end
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// Display the value that was checked
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$display("top.memory.memory[1] = %h",top.memory.memory[1]);
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$finish(0);
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end
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endmodule
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// Module containing a memory array
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module memory;
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reg [3:0] memory [0:1];
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endmodule
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// Module to instantiate test and memory modules
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module top;
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bug_test bug_test();
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memory memory();
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endmodule
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