diff --git a/ip_cores/blake2b/synth/blake2g_top.xdc b/ip_cores/blake2b/synth/blake2g_top.xdc
new file mode 100644
index 0000000..5d8cffe
--- /dev/null
+++ b/ip_cores/blake2b/synth/blake2g_top.xdc
@@ -0,0 +1 @@
+create_clock -period 2.000 -name i_clk -waveform {0.000 1.000} [get_ports -filter { NAME =~  "*clk*" && DIRECTION == "IN" }]