-       /* Macros: */
-               #if !defined(__DOXYGEN__)
-                       #define _GETADCMUXMASK2(x, y)       x ## y
-                       #define _GETADCMUXMASK(x, y)        _GETADCMUXMASK2(x, y)
+               #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