diff --git a/README.md b/README.md
index 2faab39e..6429a74d 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,24 @@
-# Arduino Core for SAM3X CPU
+# Enhanced Arduino Core for SAM3X CPU
+
+This repository is based from the [Arduio Sam SDK for cortex-m3](https://github.com/arduino/ArduinoCore-sam). The sdk was modified to include the following features which are not supported by the main repository:
+
+- Attachment of a callback function to the IRQ handler of USART/UART peripherals. This comes handy when you need to process data in real-time.
+- Addition of USART2 as Serial4.
+- Updated GCC to version 11.2.1.
+- Using by default C++20 and C17
+
+## Installation
+
+Add the following url to your Arduino package manager
+
+```
+https://raw.githubusercontent.com/vChavezB/ArduinoBoards/master/SAM3X/package_vchavezb_sam-enhanced.json
+```
+
+---
+The rest of this readme has been kept unmodified and is as-is from the original repo.
+
+---
 
 This repository contains the source code and configuration files of the Arduino Core for Atmel's SAM3X processor (used on the [Arduino Due](https://www.arduino.cc/en/Main/ArduinoBoardDue) board).
 
diff --git a/boards.txt b/boards.txt
index 55037861..2708af7c 100644
--- a/boards.txt
+++ b/boards.txt
@@ -1,5 +1,5 @@
 
-arduino_due_x_dbg.name=Arduino Due (Programming Port)
+arduino_due_x_dbg.name=Arduino Due Enhanced (Programming Port)
 arduino_due_x_dbg.vid.0=0x2341
 arduino_due_x_dbg.pid.0=0x003d
 arduino_due_x_dbg.vid.1=0x2A03
@@ -23,7 +23,7 @@ arduino_due_x_dbg.build.variant_system_lib=libsam_sam3x8e_gcc_rel.a
 arduino_due_x_dbg.build.vid=0x2341
 arduino_due_x_dbg.build.pid=0x003e
 
-arduino_due_x.name=Arduino Due (Native USB Port)
+arduino_due_x.name=Arduino Due Enhanced (Native USB Port)
 arduino_due_x.vid.0=0x2341
 arduino_due_x.pid.0=0x003e
 arduino_due_x.vid.1=0x2A03
diff --git a/cores/arduino/UARTClass.cpp b/cores/arduino/UARTClass.cpp
index 36de1358..9efbe083 100644
--- a/cores/arduino/UARTClass.cpp
+++ b/cores/arduino/UARTClass.cpp
@@ -66,7 +66,7 @@ void UARTClass::init(const uint32_t dwBaudRate, const uint32_t modeReg)
   // Configure interrupts
   _pUart->UART_IDR = 0xFFFFFFFF;
   _pUart->UART_IER = UART_IER_RXRDY | UART_IER_OVRE | UART_IER_FRAME;
-
+  
   // Enable UART interrupt in NVIC
   NVIC_EnableIRQ(_dwIrq);
 
@@ -172,7 +172,14 @@ void UARTClass::IrqHandler( void )
 
   // Did we receive data?
   if ((status & UART_SR_RXRDY) == UART_SR_RXRDY)
-    _rx_buffer->store_char(_pUart->UART_RHR);
+  {
+    uint8_t uart_rx_frame=_pUart->UART_RHR;
+    _rx_buffer->store_char(uart_rx_frame);
+    if(pRx_irq_cb != nullptr)
+    {
+        pRx_irq_cb(uart_rx_frame,rx_irq_args);
+    }
+  }
 
   // Do we need to keep sending data?
   if ((status & UART_SR_TXRDY) == UART_SR_TXRDY) 
@@ -196,3 +203,8 @@ void UARTClass::IrqHandler( void )
   }
 }
 
+void UARTClass::attachRxIrq(rx_irq_cb cb,void * args)
+{
+    pRx_irq_cb = cb;
+    rx_irq_args = args;
+}
diff --git a/cores/arduino/UARTClass.h b/cores/arduino/UARTClass.h
index 3747d8be..a85fc384 100644
--- a/cores/arduino/UARTClass.h
+++ b/cores/arduino/UARTClass.h
@@ -59,7 +59,10 @@ class UARTClass : public HardwareSerial
     uint32_t getInterruptPriority();
 
     void IrqHandler(void);
-
+    typedef void (*rx_irq_cb)(uint8_t frame,void * args);
+    
+    void attachRxIrq(rx_irq_cb cb,void * args);
+    
     operator bool() { return true; }; // UART always active
 
   protected:
@@ -69,6 +72,8 @@ class UARTClass : public HardwareSerial
     RingBuffer *_tx_buffer;
 
     Uart* _pUart;
+    rx_irq_cb pRx_irq_cb;
+    void * rx_irq_args;
     IRQn_Type _dwIrq;
     uint32_t _dwId;
 
diff --git a/cores/arduino/new.cpp b/cores/arduino/new.cpp
index f1897758..746bc338 100644
--- a/cores/arduino/new.cpp
+++ b/cores/arduino/new.cpp
@@ -34,3 +34,14 @@ void operator delete[](void * ptr) {
   free(ptr);
 }
 
+/*
+Fix for C++>14
+https://forum.arduino.cc/t/undefined-reference-to-operator-delete-void-unsigned-int/620428
+*/
+void operator delete(void* ptr, std::size_t) _GLIBCXX_USE_NOEXCEPT {
+    delete ptr;
+}
+
+void operator delete[](void* ptr, std::size_t) _GLIBCXX_USE_NOEXCEPT {
+    delete[] ptr;
+}
diff --git a/platform.txt b/platform.txt
index 5a330240..cab922ef 100644
--- a/platform.txt
+++ b/platform.txt
@@ -17,15 +17,15 @@ compiler.warning_flags.default=
 compiler.warning_flags.more=-Wall
 compiler.warning_flags.all=-Wall -Wextra
 
-compiler.path={runtime.tools.arm-none-eabi-gcc-4.8.3-2014q1.path}/bin/
+compiler.path={runtime.tools.arm-none-eabi-gcc-11.2.1-xpack.path}/bin/
 compiler.c.cmd=arm-none-eabi-gcc
-compiler.c.flags=-c -g -Os {compiler.warning_flags} -std=gnu11 -ffunction-sections -fdata-sections -nostdlib --param max-inline-insns-single=500 -Dprintf=iprintf -MMD
+compiler.c.flags=-c -g -Os {compiler.warning_flags} -std=gnu17 -ffunction-sections -fdata-sections -nostdlib --param max-inline-insns-single=500 -Dprintf=iprintf -MMD
 compiler.c.elf.cmd=arm-none-eabi-gcc
 compiler.c.elf.flags=-Os -Wl,--gc-sections
 compiler.S.cmd=arm-none-eabi-gcc
 compiler.S.flags=-c -g -x assembler-with-cpp -MMD
 compiler.cpp.cmd=arm-none-eabi-g++
-compiler.cpp.flags=-c -g -Os {compiler.warning_flags} -std=gnu++11 -ffunction-sections -fdata-sections -nostdlib -fno-threadsafe-statics --param max-inline-insns-single=500 -fno-rtti -fno-exceptions -MMD
+compiler.cpp.flags=-c -g -Os {compiler.warning_flags} -std=gnu++20 -ffunction-sections -fdata-sections -nostdlib -fno-threadsafe-statics --param max-inline-insns-single=500 -fno-rtti -fno-exceptions -MMD
 compiler.ar.cmd=arm-none-eabi-ar
 compiler.ar.flags=rcs
 compiler.objcopy.cmd=arm-none-eabi-objcopy
diff --git a/variants/arduino_due_x/variant.cpp b/variants/arduino_due_x/variant.cpp
index 7a0de80a..34ad3096 100644
--- a/variants/arduino_due_x/variant.cpp
+++ b/variants/arduino_due_x/variant.cpp
@@ -286,12 +286,12 @@ extern const PinDescription g_APinDescription[]=
   { PIOA, PIO_PA1A_CANRX0|PIO_PA0A_CANTX0, ID_PIOA, PIO_PERIPH_A, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_COMBO), NO_ADC,  NO_ADC, NOT_ON_PWM,  NOT_ON_TIMER },
   // 91 - CAN1 all pins
   { PIOB, PIO_PB15A_CANRX1|PIO_PB14A_CANTX1, ID_PIOB, PIO_PERIPH_A, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_COMBO), NO_ADC, NO_ADC, NOT_ON_PWM,  NOT_ON_TIMER },
-
+  // 92 - USART2 (Serial4) all pins
+  { PIOB, PIO_PB20A_TXD2|PIO_PB21A_RXD2, ID_PIOB, PIO_PERIPH_A, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_COMBO), NO_ADC, NO_ADC, NOT_ON_PWM, NOT_ON_TIMER },
   // END
   { NULL, 0, 0, PIO_NOT_A_PIN, PIO_DEFAULT, 0, NO_ADC, NO_ADC, NOT_ON_PWM, NOT_ON_TIMER }
 } ;
 
-
 uint8_t g_pinStatus[PINS_COUNT] = {0};
 
 #ifdef __cplusplus
@@ -321,9 +321,11 @@ void UART_Handler(void)
 RingBuffer rx_buffer2;
 RingBuffer rx_buffer3;
 RingBuffer rx_buffer4;
+RingBuffer rx_buffer5;
 RingBuffer tx_buffer2;
 RingBuffer tx_buffer3;
 RingBuffer tx_buffer4;
+RingBuffer tx_buffer5;
 
 USARTClass Serial1(USART0, USART0_IRQn, ID_USART0, &rx_buffer2, &tx_buffer2);
 void serialEvent1() __attribute__((weak));
@@ -334,6 +336,9 @@ void serialEvent2() { }
 USARTClass Serial3(USART3, USART3_IRQn, ID_USART3, &rx_buffer4, &tx_buffer4);
 void serialEvent3() __attribute__((weak));
 void serialEvent3() { }
+USARTClass Serial4(USART2, USART2_IRQn, ID_USART2, &rx_buffer5, &tx_buffer5);
+void serialEvent4() __attribute__((weak));
+void serialEvent4() { }
 
 // IT handlers
 void USART0_Handler(void)
@@ -351,6 +356,11 @@ void USART3_Handler(void)
   Serial3.IrqHandler();
 }
 
+void USART2_Handler(void)
+{
+  Serial4.IrqHandler();
+}
+
 // ----------------------------------------------------------------------------
 
 void serialEventRun(void)
@@ -359,6 +369,7 @@ void serialEventRun(void)
   if (Serial1.available()) serialEvent1();
   if (Serial2.available()) serialEvent2();
   if (Serial3.available()) serialEvent3();
+  if (Serial4.available()) serialEvent4();
 }
 
 // ----------------------------------------------------------------------------
@@ -415,6 +426,12 @@ void init( void )
     g_APinDescription[PINS_USART3].ulPinType,
     g_APinDescription[PINS_USART3].ulPin,
     g_APinDescription[PINS_USART3].ulPinConfiguration);
+    
+  PIO_Configure(
+    g_APinDescription[PINS_USART2].pPort,
+    g_APinDescription[PINS_USART2].ulPinType,
+    g_APinDescription[PINS_USART2].ulPin,
+    g_APinDescription[PINS_USART2].ulPinConfiguration);    
 
   // Initialize USB pins
   PIO_Configure(
diff --git a/variants/arduino_due_x/variant.h b/variants/arduino_due_x/variant.h
index 922b40b4..ad43b9e8 100644
--- a/variants/arduino_due_x/variant.h
+++ b/variants/arduino_due_x/variant.h
@@ -170,7 +170,8 @@ static const uint8_t SCL1 = PIN_WIRE1_SCL;
 #define PINS_USART1          (83u)
 // Serial3
 #define PINS_USART3          (84u)
-
+// Serial4
+#define PINS_USART2          (92u)
 /*
  * USB Interfaces
  */
@@ -252,7 +253,7 @@ extern UARTClass Serial;
 extern USARTClass Serial1;
 extern USARTClass Serial2;
 extern USARTClass Serial3;
-
+extern USARTClass Serial4;
 #endif
 
 // These serial port names are intended to allow libraries and architecture-neutral