Index: firmware/App/Services/SystemComm.h
===================================================================
diff -u -rdd70052b03eeb284223a4aade8567a4acec63efb -r7d4711edd7b40cd3e29f43e766f79a8a09586fe9
--- firmware/App/Services/SystemComm.h	(.../SystemComm.h)	(revision dd70052b03eeb284223a4aade8567a4acec63efb)
+++ firmware/App/Services/SystemComm.h	(.../SystemComm.h)	(revision 7d4711edd7b40cd3e29f43e766f79a8a09586fe9)
@@ -1,17 +1,17 @@
 /**************************************************************************
 *
-* Copyright (c) 2019-2020 Diality Inc. - All Rights Reserved.
+* Copyright (c) 2019-2024 Diality Inc. - All Rights Reserved.
 *
 * THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
 * WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
 *
-* @file SystemComm.h
+* @file    SystemComm.h
 *
-* @author (last) Sean
-* @date (last) 27-Feb-2020
+* @author  (last)      Michael Garthwaite
+* @date    (last)      17-Aug-2023
 *
-* @author (original) Dara Navaei
-* @date (original) 05-Nov-2019
+* @author  (original)  Dara Navaei
+* @date    (original)  05-Nov-2019
 *
 ***************************************************************************/
 
@@ -24,44 +24,41 @@
 
 /**
  *  @defgroup SystemComm SystemComm
- *  @brief System communication module.  Manages incoming and outgoing CAN frames.
+ *  @brief System communication module. Manages incoming and outgoing CAN frames.
  *
  *  @addtogroup SystemComm
  *  @{
  */
 
 // ********** public definitions **********
 
-#define MESSAGE_SYNC_BYTE           0xA5            ///< Denali message syncronization byte.
+#define MESSAGE_SYNC_BYTE                       0xA5                                                                ///< Denali message syncronization byte.
 
-#define CAN_MESSAGE_PAYLOAD_SIZE    8               ///< CAN frame payload size (in bytes).
-#ifdef DEBUG_ENABLED
-    #define PC_MESSAGE_PACKET_SIZE  8
-#endif
+#define CAN_MESSAGE_PAYLOAD_SIZE                8                                                                   ///< CAN frame payload size (in bytes).
 
-#define MSG_ID_ACK                  0xFFFF          ///< Denali message ID for acknowledging received messages (when required).
-#define MSG_ACK_BIT                 0x8000          ///< ACK bit in sequence number that indicates an ACK is required.
-#define MAX_MSG_SEQ_NO              0x7FFF          ///< Maximum sequence number for Denali message (then wraps to 1).
-#define MIN_MSG_SEQ_NO              0x0001          ///< Minimum sequence number for Denali message.
-#define MAX_ACK_MSG_SIZE            ( sizeof( MESSAGE_WRAPPER_T ) + 1 + CAN_MESSAGE_PAYLOAD_SIZE )  ///< Maximum size (in bytes) of Denali message including full (wrapped) message + sync + any CAN padding)
+#define MSG_ID_ACK_MESSAGE_THAT_REQUIRES_ACK    0xFFFF                                                              ///< Denali message ID for acknowledging received messages (when required).
+#define MSG_ACK_BIT                             0x8000                                                              ///< ACK bit in sequence number that indicates an ACK is required.
+#define MAX_MSG_SEQ_NO                          0x7FFF                                                              ///< Maximum sequence number for Denali message (then wraps to 1).
+#define MIN_MSG_SEQ_NO                          0x0001                                                              ///< Minimum sequence number for Denali message.
+#define MAX_ACK_MSG_SIZE                        ( sizeof( MESSAGE_WRAPPER_T ) + 1 + CAN_MESSAGE_PAYLOAD_SIZE )      ///< Maximum size (in bytes) of Denali message including full (wrapped) message + sync + any CAN padding)
 
-typedef COMM_BUFFER_T   CAN_MESSAGE_BOX_T;          ///< the CAN comm buffers align with the active CAN message boxes
+typedef COMM_BUFFER_T   CAN_MESSAGE_BOX_T;                                                                          ///< the CAN comm buffers align with the active CAN message boxes
 
 // ********** public function prototypes **********
 
 void initSystemComm( void );
 void execSystemCommRx( void );
 void execSystemCommTx( void );
 void handleCANMsgInterrupt( CAN_MESSAGE_BOX_T srcCANBox );
-#ifdef DEBUG_ENABLED
-    void handleUARTMsgRecvPacketInterrupt( void );
-    void handleUARTMsgXmitPacketInterrupt( void );
-#endif
 BOOL isCANBoxForXmit( CAN_MESSAGE_BOX_T srcCANBox );
 BOOL isCANBoxForRecv( CAN_MESSAGE_BOX_T srcCANBox );
 BOOL isHDCommunicating( void );
 BOOL isDGOnlyCANNode( void );
 BOOL addMsgToPendingACKList( MESSAGE_T *msg, COMM_BUFFER_T channel, U08 *msgData, U32 len );
+BOOL testSetHDCommunicationStatus( U32 value );
+BOOL testResetHDCommuncationStatus( void );
+BOOL testSetPendingACKOverride( U32 value );
+BOOL testResetPendingACKOverride( void );
 
 /**@}*/