diff --git a/hardware/sam/cores/sam/USARTClass.cpp b/hardware/sam/cores/sam/USARTClass.cpp
index a352b6321..a1b511a72 100644
--- a/hardware/sam/cores/sam/USARTClass.cpp
+++ b/hardware/sam/cores/sam/USARTClass.cpp
@@ -123,7 +123,7 @@ void USARTClass::IrqHandler( void )
   uint32_t status = _pUsart->US_CSR;
 
   // Did we receive data ?
-  if ((status & US_CSR_ENDRX) == US_CSR_ENDRX)
+  if ((status & US_CSR_RXRDY) == US_CSR_RXRDY)
     _rx_buffer->store_char( _pUsart->US_RHR ) ;
 
   // Acknowledge errors
diff --git a/hardware/sam/variants/arduino_due/variant.cpp b/hardware/sam/variants/arduino_due/variant.cpp
index e13ab3ccf..3f6b4b6cd 100644
--- a/hardware/sam/variants/arduino_due/variant.cpp
+++ b/hardware/sam/variants/arduino_due/variant.cpp
@@ -326,8 +326,28 @@ extern void init( void )
   WDT_Disable( WDT ) ;
 
   // Initialize Serial port UART, common to all SAM3 variants
-  PIO_Configure( g_APinDescription[PINS_UART].pPort, g_APinDescription[PINS_UART].ulPinType,
-                 g_APinDescription[PINS_UART].ulPin, g_APinDescription[PINS_UART].ulPinConfiguration ) ;
+  PIO_Configure(
+    g_APinDescription[PINS_UART].pPort,
+    g_APinDescription[PINS_UART].ulPinType,
+    g_APinDescription[PINS_UART].ulPin,
+    g_APinDescription[PINS_UART].ulPinConfiguration);
+
+  // Initialize Serial ports USART
+  PIO_Configure(
+    g_APinDescription[PINS_USART0].pPort,
+    g_APinDescription[PINS_USART0].ulPinType,
+    g_APinDescription[PINS_USART0].ulPin,
+    g_APinDescription[PINS_USART0].ulPinConfiguration);
+  PIO_Configure(
+    g_APinDescription[PINS_USART1].pPort,
+    g_APinDescription[PINS_USART1].ulPinType,
+    g_APinDescription[PINS_USART1].ulPin,
+    g_APinDescription[PINS_USART1].ulPinConfiguration);
+  PIO_Configure(
+    g_APinDescription[PINS_USART2].pPort,
+    g_APinDescription[PINS_USART2].ulPinType,
+    g_APinDescription[PINS_USART2].ulPin,
+    g_APinDescription[PINS_USART2].ulPinConfiguration);
 
   // Initialize 10bit Analog Controller
   /* Enable peripheral clock.*/