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|
`timescale 1us/1us
module debounce_tb (
);
logic rst_i;
logic clk_i;
logic signal_i;
logic signal_o;
integer i = 0;
debounce #(.STABLE_PERIOD(5)) uut (
.rst_i(rst_i),
.clk_i(clk_i),
.signal_i(signal_i),
.signal_o(signal_o)
);
string filename;
initial begin
`ifdef DUMP_FILE_NAME
filename=`DUMP_FILE_NAME;
`else
filename="debounce.lxt2";
`endif
$dumpfile(filename); $dumpvars();
clk_i = 0;
rst_i = 1'b1;
signal_i = 1'b1;
#1
rst_i = 1'b0;
#1
rst_i = 1'b1;
end
always #10 clk_i = ~clk_i;
initial begin
// initial key press
@(negedge clk_i);
signal_i = ~signal_i;
assert (signal_o == 1'b1);
repeat(2) @(negedge clk_i);
signal_i = ~signal_i;
assert (signal_o == 1'b1);
// try bouncing
repeat(2) @(negedge clk_i);
for (i=0; i < 20; i = i + 1) begin
@(negedge clk_i);
signal_i = ~signal_i;
assert (signal_o == 1'b1);
end
@(negedge clk_i);
signal_i = ~signal_i;
assert (signal_o == 1'b1);
repeat(10) @(negedge clk_i);
assert (signal_o == 1'b0);
repeat(10) @(negedge clk_i);
signal_i = ~signal_i;
repeat(10) @(negedge clk_i);
assert (signal_o == 1'b1);
repeat(10) @(negedge clk_i);
$finish();
end
endmodule
|
