diff --git a/lib/CPUs/MIPS/syn/ise101/project/mips_top.xcf b/lib/CPUs/MIPS/syn/ise101/project/mips_top.xcf
index a00749d..3771aac 100644
--- a/lib/CPUs/MIPS/syn/ise101/project/mips_top.xcf
+++ b/lib/CPUs/MIPS/syn/ise101/project/mips_top.xcf
@@ -1,10 +1,13 @@
-# Bus clock nets
-NET "CLK_I" TNM_NET = "sys_clk";
-TIMESPEC "TS_clk" = PERIOD "sys_clk" 9.9 ns HIGH 50 %;
-
+# CPU clock nets
 NET "cpu_clk" TNM_NET = "cpu_clk";
 TIMESPEC "TS_cpu_clk" = PERIOD "cpu_clk" 9.9 ns HIGH 50 %;
 
+# Bus clock nets
+NET "CLK_I" TNM_NET = "bus_clk";
+TIMESPEC "TS_bus_clk" = PERIOD "bus_clk" 9.9 ns HIGH 50 %;
+TIMESPEC "TS_unrelate_bus_clk" = FROM cpu_clk TO bus_clk TIG;
+
+
 BEGIN MODEL biu
 	INST inst_bin_fifo ram_style = distributed;
 	INST inst_bout_fifo ram_style = distributed;