diff --git a/src/user_interface.cpp b/src/user_interface.cpp
new file mode 100644
index 0000000..e51b206
--- /dev/null
+++ b/src/user_interface.cpp
@@ -0,0 +1,43 @@
+/**
+ * @file These are implementations of the user interfaces declared in
+ *       hei_user_interface.hpp
+ */
+
+#include <hei_user_interface.hpp>
+
+namespace libhei
+{
+
+//------------------------------------------------------------------------------
+
+ReturnCode registerRead(const Chip& i_chip, void* o_buffer, size_t& io_bufSize,
+                        uint64_t i_regType, uint64_t i_address)
+{
+    ReturnCode rc = RC_SUCCESS;
+
+    //    HEI_INF("registerRead(%p,%p,%lx,%lx,%lx)", i_chip.getChip(),
+    //             o_buffer, io_bufSize, i_regType, i_address);
+
+    return rc;
+}
+
+//------------------------------------------------------------------------------
+
+#ifndef __HEI_READ_ONLY
+
+ReturnCode registerWrite(const Chip& i_chip, void* i_buffer, size_t& io_bufSize,
+                         uint64_t i_regType, uint64_t i_address)
+{
+    ReturnCode rc = RC_SUCCESS;
+
+    //    HEI_INF("registerWrite(%p,%p,%lx,%lx,%lx)", i_chip.getChip(),
+    //             i_buffer, io_bufSize, i_regType, i_address);
+
+    return rc;
+}
+
+#endif
+
+//------------------------------------------------------------------------------
+
+} // namespace libhei