mirror of
https://github.com/steveicarus/iverilog.git
synced 2026-08-28 16:53:45 +02:00
Stephen Williams
cea237b407
By adding ivtest to the iverilog source tree, it is easier to keep the regression test synchronized with the source that is being tested. This should be especially helpful for PRs that add a new feature, and have a matching ivtest PR with the regression test for that feature.
88 lines
2.4 KiB
Verilog
88 lines
2.4 KiB
Verilog
/*
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* Copyright (c) 2000 Guy Hutchison ([email protected])
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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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module pullupdown;
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// declare several bussed wires
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wire pull_up_1, pull_down_1;
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wire [7:0] pull_up_8, pull_down_8;
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reg error;
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// assign pullups to each wire
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pullup (pull_up_1);
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pulldown (pull_down_1);
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pullup u8 [7:0] (pull_up_8);
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pulldown d8 [7:0] (pull_down_8);
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// create tristate drivers for each wire
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reg driver_1;
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reg [7:0] driver_8;
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reg driver_1_en, driver_8_en;
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assign pull_up_1 = (driver_1_en) ? driver_1 : 1'bz;
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assign pull_down_1 = (driver_1_en) ? driver_1 : 1'bz;
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assign pull_up_8 = (driver_8_en) ? driver_8 : 8'bz;
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assign pull_down_8 = (driver_8_en) ? driver_8 : 8'bz;
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initial
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begin : test_block
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integer i;
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// turn off all drivers
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driver_1_en = 0;
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driver_8_en = 0;
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error = 0;
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#1;
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// check default values
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if ((pull_up_1 !== 1'b1) || (pull_down_1 !== 1'b0) ||
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(pull_up_8 !== 8'hFF) || (pull_down_8 !== 8'h00))
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error = 1;
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// turn on drivers
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driver_1_en = 1;
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driver_8_en = 1;
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for (i=0; i<256; i=i+1)
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begin
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driver_1 = ~driver_1;
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driver_8 = i;
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$display ("Testing drivers with value %h", driver_8);
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#1;
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check_drivers;
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#10;
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end
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if (error)
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$display ("FAILED - pullupdown ");
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else $display ("PASSED");
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end // block: test_block
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task check_drivers;
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begin
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if ((pull_up_1 !== driver_1) || (pull_down_1 !== driver_1) ||
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(pull_up_8 !== driver_8) || (pull_down_8 !== driver_8))
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error = 1;
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end
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endtask // check_drivers
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endmodule // pullupdown
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