-               #include "ISP/ISPProtocol.h"\r
-               #include "XPROG/XPROGProtocol.h"\r
-\r
-       /* Preprocessor Checks: */\r
-               #if ((BOARD == BOARD_XPLAIN) || (BOARD == BOARD_XPLAIN_REV1))\r
-                       #undef ENABLE_ISP_PROTOCOL\r
-                       \r
-                       #if !defined(ENABLE_XPROG_PROTOCOL)\r
-                               #define ENABLE_XPROG_PROTOCOL\r
-                       #endif\r
-               #endif\r
-
-       /* Macros: */\r
-               /** Programmer ID string, returned to the host during the CMD_SIGN_ON command processing */
-               #define PROGRAMMER_ID       "AVRISP_MK2"\r
-               \r
-               /** Timeout period for each issued command from the host before it is aborted */\r
-               #define COMMAND_TIMEOUT_MS   200\r
-               \r
-               /** Command timeout counter register, GPIOR for speed */\r
-               #define TimeoutMSRemaining   GPIOR0\r
-\r
-       /* External Variables: */\r
-               extern uint32_t CurrentAddress;\r
-               extern bool     MustSetAddress;\r
-\r
-       /* Function Prototypes: */\r
-               void V2Protocol_ProcessCommand(void);\r
-               \r
-               #if defined(INCLUDE_FROM_V2PROTOCOL_C)\r
-                       static void V2Protocol_UnknownCommand(uint8_t V2Command);\r
-                       static void V2Protocol_SignOn(void);\r
-                       static void V2Protocol_GetSetParam(uint8_t V2Command);\r
-                       static void V2Protocol_ResetProtection(void);\r
-                       static void V2Protocol_LoadAddress(void);\r
+               #include "ISP/ISPProtocol.h"
+               #include "XPROG/XPROGProtocol.h"
+
+       /* Preprocessor Checks: */
+               #if ((BOARD == BOARD_XPLAIN) || (BOARD == BOARD_XPLAIN_REV1))
+                       #undef ENABLE_ISP_PROTOCOL
+
+                       #if !defined(ENABLE_XPROG_PROTOCOL)
+                               #define ENABLE_XPROG_PROTOCOL
+                       #endif
+               #endif
+
+               #if defined(USB_SERIES_4_AVR) && ((VTARGET_ADC_CHANNEL == 2) || (VTARGET_ADC_CHANNEL == 3))
+                       #error The U4 AVR chips do not contain ADC channels 2 or 3. Please change VTARGET_ADC_CHANNEL or define NO_VTARGET_DETECT in the makefile.
+               #endif
+               
+               #if defined(VTARGET_USE_INTERNAL_REF)
+                       #undef  VTARGET_REF_VOLTS
+                       #define VTARGET_REF_VOLTS 2.56
+                       
+                       #define VTARGET_REF_MASK ADC_REFERENCE_INT2560MV
+               #else
+                       #define VTARGET_REF_MASK ADC_REFERENCE_AVCC
+               #endif
+
+       /* Macros: */
+               /** Programmer ID string, returned to the host during the CMD_SIGN_ON command processing. */
+               #define PROGRAMMER_ID              "AVRISP_MK2"
+
+               /** Timeout period for each issued command from the host before it is aborted (in 10ms ticks). */
+               #define COMMAND_TIMEOUT_TICKS      100
+
+               /** Command timeout expiration flag, GPIOR for speed. */
+               #define TimeoutExpired             GPIOR1
+
+               /** MUX mask for the VTARGET ADC channel number. */
+               #define VTARGET_ADC_CHANNEL_MASK   ADC_GET_CHANNEL_MASK(VTARGET_ADC_CHANNEL)
+
+       /* External Variables: */
+               extern uint32_t CurrentAddress;
+               extern bool     MustLoadExtendedAddress;
+
+       /* Function Prototypes: */
+               void V2Protocol_Init(void);
+               void V2Protocol_ProcessCommand(void);
+
+               #if defined(INCLUDE_FROM_V2PROTOCOL_C)
+                       static void V2Protocol_UnknownCommand(const uint8_t V2Command);
+                       static void V2Protocol_SignOn(void);
+                       static void V2Protocol_GetSetParam(const uint8_t V2Command);
+                       static void V2Protocol_ResetProtection(void);
+                       static void V2Protocol_LoadAddress(void);