diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..a6a3ac0
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "verilog/rtl/waveform-generator"]
+	path = verilog/rtl/waveform-generator
+	url = https://codeberg.org/mole99/waveform-generator
diff --git a/verilog/rtl/waveform-generator b/verilog/rtl/waveform-generator
new file mode 160000
index 0000000..3afa6c9
--- /dev/null
+++ b/verilog/rtl/waveform-generator
@@ -0,0 +1 @@
+Subproject commit 3afa6c9c8eb7268c48bfb7fba8a825d9a69643f2