diff --git a/lib/CPUs/MIPS/syn/ise101/constraints/mips_top.xcf b/lib/CPUs/MIPS/syn/ise101/constraints/mips_top.xcf
new file mode 100644
index 0000000..5d908f7
--- /dev/null
+++ b/lib/CPUs/MIPS/syn/ise101/constraints/mips_top.xcf
@@ -0,0 +1,6 @@
+BEGIN MODEL biu
+	INST inst_bin_fifo ram_style = distributed;
+	INST inst_bout_fifo ram_style = distributed;
+	INST inst_write_fifo ram_style = distributed;
+END;
+