Index: firmware/App/Drivers/CPLD.c
===================================================================
diff -u -r30f049651877229042e3f8700c8596e5b9a1e0f4 -rcd5be724d5a3ba7457e761191d82f278654d7f5c
--- firmware/App/Drivers/CPLD.c	(.../CPLD.c)	(revision 30f049651877229042e3f8700c8596e5b9a1e0f4)
+++ firmware/App/Drivers/CPLD.c	(.../CPLD.c)	(revision cd5be724d5a3ba7457e761191d82f278654d7f5c)
@@ -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 CPLD.c
+* @file    CPLD.c
 *
-* @author (last) Sean Nash
-* @date (last) 24-Sep-2020
+* @author  (last)      Sean Nash
+* @date    (last)      03-Apr-2023
 *
-* @author (original) Dara Navaei
-* @date (original) 05-Nov-2019
+* @author  (original)  Dara Navaei
+* @date    (original)  05-Nov-2019
 *
 ***************************************************************************/
 
@@ -43,11 +43,13 @@
 #define GREEN_SPI5_PORT_MASK        0x00000200              ///< (CLK     - re-purposed as output GPIO) for green alarm lamp signal.
 #define BLUE_SPI5_PORT_MASK         0x00000400              ///< (SIMO[0] - re-purposed as output GPIO) for blue alarm lamp signal.
 #define RED_SPI5_PORT_MASK          0x00000800              ///< (SOMI[0] - re-purposed as output GPIO) for red alarm lamp signal.
+#define AC_PRESENT_SPI5_PORT_MASK   0x00000001              ///< (SOMI[0] - re-purposed as output GPIO) for red alarm lamp signal.
 
 // CPLD pin I/O macros
 #define GET_OFF()          (PIN_SIGNAL_STATE_T)(gioGetBit(gioPORTA, OFF_BUTTON_GIO_PORT_PIN))   ///< Macro to get off button signal state.
 #define GET_STOP()         (PIN_SIGNAL_STATE_T)(gioGetBit(gioPORTA, STOP_BUTTON_GIO_PORT_PIN))  ///< Macro to get stop button signal state.
-#define GET_WD_EXP()       (PIN_SIGNAL_STATE_T)(gioGetBit(gioPORTB, WD_EXP_GIO_PORT_PIN))       ///< Macro to get watchdog expired signal state.
+#define GET_WD_EXP()       (PIN_SIGNAL_STATE_T)(gioGetBit(gioPORTB, WD_EXP_GIO_PORT_PIN))       ///< Macro to get watchdog expired signal state.
+#define GET_AC_PRESENT()   (PIN_SIGNAL_STATE_T)(mibspiREG5->PC2 & AC_PRESENT_SPI5_PORT_MASK)    ///< Macro to get A/C power present signal state.
 
 #define TGL_WD_PET()       gioToggleBit( gioPORTB, WD_PET_GIO_PORT_PIN )                        ///< Macro to toggle watchdog pet signal state.
 #define TGL_OFF_REQ()      gioToggleBit( gioPORTB, OFF_REQUEST_GIO_PORT_PIN)                    ///< Macro to toggle power off request signal state.
@@ -110,6 +112,22 @@
     PIN_SIGNAL_STATE_T level = GET_WD_EXP();
 
     return level;
+}
+
+/*********************************************************************//**
+ * @brief
+ * The getCPLDACPowerLossDetected function determines whether the CPLD is
+ * reporting A/C power has been lost.
+ * @details Inputs: Signal from CPLD on A/C presence pin.
+ * @details Outputs: none
+ * @return TRUE if A/C power loss is detected, FALSE if not
+ *************************************************************************/
+BOOL getCPLDACPowerLossDetected( void )
+{
+    PIN_SIGNAL_STATE_T acLevel = GET_AC_PRESENT();
+    BOOL acLost = ( PIN_SIGNAL_HIGH == acLevel ? FALSE : TRUE );
+
+    return acLost;
 }
 
 /*********************************************************************//**