NET "glitch_detect"  LOC =  "P42";
NET "clk_in"         LOC =  "P80";
NET "bad_clk"        LOC =  "P41";

INST    s1           LOC = "CLB_R15C1.S0";          # place FF2 close to XOR LUT (C37)
INST    s3           LOC = "CLB_R15C1.S1";          # place FF3 close to XOR LUT (C37)
INST    l_xor        LOC = "CLB_R15C1.S1";          # XOR LUT
INST    s2           LOC = "CLB_R15C30.S0";         # place FF1, FAR from FF2, so the glitch will be VERY big
                                                    # modify the column C30 to set routing delay

NET "bad_clk"       drive=24;
NET "bad_clk"       FAST;
NET "glitch_detect" drive=6;
NET "glitch_detect" SLOW;