Index: TDDefs.h
===================================================================
diff -u -rd18cd031dcff2fc807ce158cbb4aadfda10fd3cd -r819b88d6ef2329a7f07697e35dc00396d6ccefc2
--- TDDefs.h	(.../TDDefs.h)	(revision d18cd031dcff2fc807ce158cbb4aadfda10fd3cd)
+++ TDDefs.h	(.../TDDefs.h)	(revision 819b88d6ef2329a7f07697e35dc00396d6ccefc2)
@@ -7,8 +7,8 @@
 *
 * @file    TDDefs.h
 *
-* @author  (last)      Praneeth Bunne
-* @date    (last)      21-May-2026
+* @author  (last)      Dara Navaei
+* @date    (last)      27-May-2026
 *
 * @author  (original)  Sean Nash
 * @date    (original)  01-Aug-2024
@@ -35,6 +35,7 @@
     MODE_PRET,                           ///< Pre-Treatment mode
     MODE_TREA,                           ///< Treatment mode
     MODE_POST,                           ///< Post-Treatment mode
+    MODE_UPDT,                           ///< Update mode
     MODE_NLEG,                           ///< Not legal - an illegal mode transition occurred
     NUM_OF_MODES                         ///< Number of TD operation modes
 };
@@ -113,6 +114,22 @@
 /**@}*/
 
 /**
+ *  @addtogroup TDUpdateMode
+ *  @{
+ */
+
+/// Sub-mode states while in update mode
+enum TD_Update_States
+{
+    TD_UPDATE_INIT_STATE = 0,                                    ///< Start update state.
+    TD_UPDATE_RESET_MCU_STATE,                                   ///< Reset MCU state.
+    NUM_OF_TD_UPDATE_STATES                                      ///< Number of update states (sub-modes).
+};
+typedef enum TD_Update_States TD_UPDATE_STATE_T;                 ///< Type for TD update states enumeration
+
+/**@}*/
+
+/**
  *  @addtogroup TDPreTreatmentMode
  *  @{
  */