[定义用户约束文件top_constraints.ucf]
NET "clk" LOC="p80";
NET "RX" LOC="p3";
NET "RXD" LOC="p200";
NET "TXD" LOC="p199";
NET "TX_ena" LOC="p10";
NET "RX_done" LOC="p145";
NET "RX_reset" LOC="p15";
NET "TX_reset" LOC="p16";
NET "CLKLXENABLE" LOC="p152";
NET "Display<0>" LOC="p108";
NET "Display<1>" LOC="p109";
NET "Display<2>" LOC="p110";
NET "Display<3>" LOC="p111”;
NET "Display<4>" LOC="p112";
NET "Display<5>" LOC="p113";
NET "Display<6>" LOC="p114";
NET "Control<0>" LOC="p120";
NET "Control<1>" LOC="p121";
NET "Control<2>" LOC="p122";
NET "Control<3>" LOC="p123";
NET "DECRYPT" LOC="p6";