Added alternate ports 44,45 to make the SWCLK and SWDIO pins available

when no debugger is being used.
BTW. The presence of a debugger can be checked via:
if (DSU->STATUSB.bit.DBGPRES) ...

Author: helmut64

variants/arduino_zero/variant.cpp

@@ -96,6 +96,10 @@
  * |            | GND              |        |                 |
  * | 42         | AREF             |  PA03  |                 | EIC/EXTINT[3] *[ADC|DAC]/VREFA ADC/AIN[1] PTC/Y[1]
  * +------------+------------------+--------+-----------------+--------------------------------------------------------------------------------------------------------
+ * | 43         |                  |  PA02  |                 | Alternate use of A0 (DAC output)
+ * | 44         |                  |  PA30  |                 | SWCLK, alternate use EXTINT[10] TCC1/WO[0] SERCOM1/PAD[2]
+ * | 45         |                  |  PA31  |                 | SWDIO, alternate use EXTINT[11] TCC1/WO[1] SERCOM1/PAD[3]
+ * +------------+------------------+--------+-----------------+--------------------------------------------------------------------------------------------------------
  * |            |32.768KHz Crystal |        |                 |
  * +------------+------------------+--------+-----------------+--------------------------------------------------------------------------------------------------------
  * |            |                  |  PA00  | XIN32           | EIC/EXTINT[0] SERCOM1/PAD[0] TCC2/WO[0]
@@ -193,8 +197,10 @@ const PinDescription g_APinDescription[]=
   { PORTA, 3, PIO_ANALOG, PIN_ATTR_ANALOG, No_ADC_Channel, NOT_ON_PWM, NOT_ON_TIMER, EXTERNAL_INT_NONE }, // DAC/VREFP
 
   // ----------------------
-  // 43 - Alternate use of A0 (DAC output)
+  // 43..45 - Alternate use of A0 (DAC output), 44 SWCLK, 45, SWDIO
   { PORTA,  2, PIO_ANALOG, PIN_ATTR_ANALOG, DAC_Channel0, NOT_ON_PWM, NOT_ON_TIMER, EXTERNAL_INT_2 }, // DAC/VOUT
+  { PORTA, 30, PIO_PWM, PIN_ATTR_DIGITAL|PIO_SERCOM, No_ADC_Channel, NOT_ON_PWM, TCC1_CH0, EXTERNAL_INT_10 }, // SWCLK
+  { PORTA, 31, PIO_PWM, PIN_ATTR_DIGITAL|PIO_SERCOM, No_ADC_Channel, NOT_ON_PWM, TCC1_CH1, EXTERNAL_INT_11 }, // SWDIO
 } ;
 
 const void* g_apTCInstances[TCC_INST_NUM+TC_INST_NUM]={ TCC0, TCC1, TCC2, TC3, TC4, TC5 } ;