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module ffnand_test;
wire q, qbar;
reg preset, clear;
parameter d = 10;
ffnand ff1(q, qbar, preset, clear);
initial
begin
#d preset = 0; clear = 1;
#d preset = 1;
#d clear = 0;
#d clear = 1;
end
initial $monitor($time,, "preset=%b clear=%b q=%b qbar=%b",
preset, clear,q, qbar);
endmodule
module ffnand(ffq, ffqbar, ffpreset, ffclear);
output ffq, ffqbar;
input ffpreset, ffclear;
nand #(1, 1) q1(ffq, ffqbar, ffpreset), q2(ffqbar, ffq, ffclear);
specify
specparam pr = 5;
specparam pf = 5;
// notice error because no path delay to ffqbar
(ffpreset => ffq) = (pr, pf);
(ffclear => ffq) = (pr, pf);
endspecify
endmodule
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