diff --git a/cores/arduino/WInterrupts.c b/cores/arduino/WInterrupts.c
index 93d888200..2c6ed74e1 100644
--- a/cores/arduino/WInterrupts.c
+++ b/cores/arduino/WInterrupts.c
@@ -25,16 +25,12 @@
 extern "C" {
 #endif
 
-static struct
-{
-  uint32_t _ulPin ;
-  voidFuncPtr _callback ;
-} callbacksInt[EXTERNAL_NUM_INTERRUPTS] ;
+static voidFuncPtr callbacksInt[EXTERNAL_NUM_INTERRUPTS];
 
 /* Configure I/O interrupt sources */
 static void __initialize()
 {
-  memset( callbacksInt, 0, sizeof( callbacksInt ) ) ;
+  memset(callbacksInt, 0, sizeof(callbacksInt));
 
   NVIC_DisableIRQ( EIC_IRQn ) ;
   NVIC_ClearPendingIRQ( EIC_IRQn ) ;
@@ -76,6 +72,8 @@ void attachInterrupt(uint32_t pin, voidFuncPtr callback, uint32_t mode)
 
   if (digitalPinToInterrupt(pin) == NOT_AN_INTERRUPT)
     return;
+  if (digitalPinToInterrupt(pin) == EXTERNAL_INT_NMI)
+    return;
 
   if (!enabled) {
     __initialize();
@@ -86,94 +84,55 @@ void attachInterrupt(uint32_t pin, voidFuncPtr callback, uint32_t mode)
   pinPeripheral(pin, PIO_EXTINT);
 
   // Assign callback to interrupt
-  callbacksInt[digitalPinToInterrupt(pin)]._ulPin = pin;
-  callbacksInt[digitalPinToInterrupt(pin)]._callback = callback;
-
-  // Check if normal interrupt or NMI
-  if (pin != 2)
-  {
-    // Look for right CONFIG register to be addressed
-    if (digitalPinToInterrupt(pin) > EXTERNAL_INT_7) {
-      config = 1;
-    } else {
-      config = 0;
-    }
-
-    // Configure the interrupt mode
-    pos = ((digitalPinToInterrupt(pin) - (8 * config)) << 2);
-    switch (mode)
-    {
-      case LOW:
-        EIC->CONFIG[config].reg |= EIC_CONFIG_SENSE0_LOW_Val << pos;
-        break;
-
-      case HIGH:
-        EIC->CONFIG[config].reg |= EIC_CONFIG_SENSE0_HIGH_Val << pos;
-        break;
+  callbacksInt[digitalPinToInterrupt(pin)] = callback;
 
-      case CHANGE:
-        EIC->CONFIG[config].reg |= EIC_CONFIG_SENSE0_BOTH_Val << pos;
-        break;
-
-      case FALLING:
-        EIC->CONFIG[config].reg |= EIC_CONFIG_SENSE0_FALL_Val << pos;
-        break;
-
-      case RISING:
-        EIC->CONFIG[config].reg |= EIC_CONFIG_SENSE0_RISE_Val << pos;
-        break;
-    }
-
-    // Enable the interrupt
-    EIC->INTENSET.reg = EIC_INTENSET_EXTINT(1 << digitalPinToInterrupt(pin));
+  // Look for right CONFIG register to be addressed
+  if (digitalPinToInterrupt(pin) > EXTERNAL_INT_7) {
+    config = 1;
+  } else {
+    config = 0;
   }
-  else // Handles NMI on pin 2
+
+  // Configure the interrupt mode
+  pos = ((digitalPinToInterrupt(pin) - (8 * config)) << 2);
+  switch (mode)
   {
-    // Configure the interrupt mode
-    switch (mode)
-    {
-      case LOW:
-        EIC->NMICTRL.reg = EIC_NMICTRL_NMISENSE_LOW;
-        break;
+    case LOW:
+      EIC->CONFIG[config].reg |= EIC_CONFIG_SENSE0_LOW_Val << pos;
+      break;
 
-      case HIGH:
-        EIC->NMICTRL.reg = EIC_NMICTRL_NMISENSE_HIGH;
-        break;
+    case HIGH:
+      EIC->CONFIG[config].reg |= EIC_CONFIG_SENSE0_HIGH_Val << pos;
+      break;
 
-      case CHANGE:
-        EIC->NMICTRL.reg = EIC_NMICTRL_NMISENSE_BOTH;
-        break;
+    case CHANGE:
+      EIC->CONFIG[config].reg |= EIC_CONFIG_SENSE0_BOTH_Val << pos;
+      break;
 
-      case FALLING:
-        EIC->NMICTRL.reg = EIC_NMICTRL_NMISENSE_FALL;
-        break;
+    case FALLING:
+      EIC->CONFIG[config].reg |= EIC_CONFIG_SENSE0_FALL_Val << pos;
+      break;
 
-      case RISING:
-        EIC->NMICTRL.reg= EIC_NMICTRL_NMISENSE_RISE;
-        break;
-    }
+    case RISING:
+      EIC->CONFIG[config].reg |= EIC_CONFIG_SENSE0_RISE_Val << pos;
+      break;
   }
+
+  // Enable the interrupt
+  EIC->INTENSET.reg = EIC_INTENSET_EXTINT(1 << digitalPinToInterrupt(pin));
 }
 
 /*
  * \brief Turns off the given interrupt.
  */
-void detachInterrupt( uint32_t ulPin )
+void detachInterrupt(uint32_t pin)
 {
-/*
-  // Retrieve pin information
-  Pio *pio = g_APinDescription[pin].pPort;
-  uint32_t mask = g_APinDescription[pin].ulPin;
-
-  // Disable interrupt
-  pio->PIO_IDR = mask;
-*/
-  if ( digitalPinToInterrupt( ulPin ) == NOT_AN_INTERRUPT )
-  {
-    return ;
-  }
+  if (digitalPinToInterrupt(pin) == NOT_AN_INTERRUPT)
+    return;
+  if (digitalPinToInterrupt(pin) == EXTERNAL_INT_NMI)
+    return;
 
-  EIC->INTENCLR.reg = EIC_INTENCLR_EXTINT( 1 << digitalPinToInterrupt( ulPin ) ) ;
+  EIC->INTENCLR.reg = EIC_INTENCLR_EXTINT(1 << digitalPinToInterrupt(pin));
 }
 
 /*
@@ -189,9 +148,8 @@ void EIC_Handler( void )
     if ( (EIC->INTFLAG.reg & ( 1 << ul ) ) != 0 )
     {
       // Call the callback function if assigned
-      if ( callbacksInt[ul]._callback != NULL )
-      {
-        callbacksInt[ul]._callback() ;
+      if (callbacksInt[ul]) {
+        callbacksInt[ul]();
       }
 
       // Clear the interrupt
@@ -200,21 +158,6 @@ void EIC_Handler( void )
   }
 }
 
-/*
- * External Non-Maskable Interrupt Controller NVIC Interrupt Handler
- */
-void NMI_Handler( void )
-{
-  // Call the callback function if assigned
-  if ( callbacksInt[EXTERNAL_INT_NMI]._callback != NULL )
-  {
-    callbacksInt[EXTERNAL_INT_NMI]._callback() ;
-  }
-
-  // Clear the interrupt
-  EIC->NMIFLAG.reg = EIC_NMIFLAG_NMI ;
-}
-
 #ifdef __cplusplus
 }
 #endif