diff --git a/src/hei_types.hpp b/src/hei_types.hpp
new file mode 100644
index 0000000..4402bde
--- /dev/null
+++ b/src/hei_types.hpp
@@ -0,0 +1,29 @@
+/**
+ * @file hei_types.hpp
+ *
+ * This file contains simple types/enums used throughout all of the isolator
+ * code.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+namespace libhei
+{
+
+/**
+ * Each Chip Data File will contain a 32-bit number representing the type of
+ * chip characterized by the file. That value must also be provide by the user
+ * application for each chip used in isolation so the isolator will know which
+ * Chip Data File to reference.
+ */
+typedef uint32_t ChipType_t;
+
+/**
+ * This is used for error checking. If a chip type contains this value, it is
+ * not a valid chip type.
+ */
+static constexpr ChipType_t DEFAULT_CHIP_TYPE = 0;
+
+} // end namespace libhei