diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..9eb315f
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "hdmi-out-test/digilent.ipdefs"]
+	path = hdmi-out-test/digilent.ipdefs
+	url = https://github.com/Digilent/vivado-library.git