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//======================================================================
//
// tb_toggle
// ---------
// Testbench for the gpio pin toggler.
//
//
// Author: Joachim Strombergson
// Copyright (c) 2018, NORDUnet A/S
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
// - Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// - Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// - Neither the name of the NORDUnet nor the names of its contributors may
// be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//======================================================================
module tb_toggle();
parameter CLK_HALF_PERIOD = 1;
parameter CLK_PERIOD = 2 * CLK_HALF_PERIOD;
reg tb_sys_clk;
reg tb_reset_n;
wire [7 : 0] tb_gpio_b;
reg [31 : 0] cycle_ctr;
toggle dut(
.sys_clk(tb_sys_clk),
.reset_n(tb_reset_n),
.gpio_b(tb_gpio_b)
);
//----------------------------------------------------------------
// clk_gen
//
// Always running clock generator process.
//----------------------------------------------------------------
always
begin : clk_gen
#CLK_HALF_PERIOD;
tb_sys_clk = !tb_sys_clk;
end // clk_gen
//----------------------------------------------------------------
// sys_monitor()
//
// An always running process that creates a cycle counter and
// conditionally displays information about the DUT.
//----------------------------------------------------------------
always
begin : sys_monitor
cycle_ctr = cycle_ctr + 1;
#(CLK_PERIOD);
$display("cycle: 0x%016x gpio_b: 0x%08x toggle_ctr: 0x%08x toggle_reg: 0x%01x",
cycle_ctr, tb_gpio_b, dut.toggle_ctr_reg, dut.toggle_reg);
end
//----------------------------------------------------------------
// init_sim()
//
// Initialize all counters and testbed functionality as well
// as setting the DUT inputs to defined values.
//----------------------------------------------------------------
initial
begin
cycle_ctr = 0;
tb_sys_clk = 0;
tb_reset_n = 0;
#(CLK_PERIOD * 10);
tb_reset_n = 1;
#(CLK_PERIOD * 10000);
$finish;
end
endmodule // tb_toggle
//======================================================================
// EOF tb_toggle.v
//======================================================================
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