added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

Revision:
0:9b334a45a8ff
Child:
22:9c52de9bc1d7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/serial_api.c	Thu Oct 01 15:25:22 2015 +0300
@@ -0,0 +1,1829 @@
+/***************************************************************************//**
+ * @file serial_api.c
+ *******************************************************************************
+ * @section License
+ * <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b>
+ *******************************************************************************
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ *
+ * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no
+ * obligation to support this Software. Silicon Labs is providing the
+ * Software "AS IS", with no express or implied warranties of any kind,
+ * including, but not limited to, any implied warranties of merchantability
+ * or fitness for any particular purpose or warranties against infringement
+ * of any proprietary rights of a third party.
+ *
+ * Silicon Labs will not be liable for any consequential, incidental, or
+ * special damages, or any other relief, or for any claim by any third party,
+ * arising from your use of this Software.
+ *
+ ******************************************************************************/
+
+#include "device.h"
+#include "clocking.h"
+#if DEVICE_SERIAL
+
+#include "mbed_assert.h"
+#include "serial_api.h"
+#include <string.h>
+#include <stdbool.h>
+
+#include "pinmap.h"
+#include "pinmap_function.h"
+#include "PeripheralPins.h"
+#include "PeripheralNames.h"
+
+#include "em_usart.h"
+#include "em_leuart.h"
+#include "em_cmu.h"
+#include "em_dma.h"
+#include "dma_api_HAL.h"
+#include "dma_api.h"
+#include "sleep_api.h"
+#include "buffer.h"
+#include "sleepmodes.h"
+
+#define SERIAL_LEAST_ACTIVE_SLEEPMODE EM1
+#define SERIAL_LEAST_ACTIVE_SLEEPMODE_LEUART EM2
+
+/** Validation of LEUART register block pointer reference
+ *  for assert statements. */
+#if !defined(LEUART_COUNT)
+#define LEUART_REF_VALID(ref)    (0)
+#elif (LEUART_COUNT == 1)
+#define LEUART_REF_VALID(ref)    ((ref) == LEUART0)
+#elif (LEUART_COUNT == 2)
+#define LEUART_REF_VALID(ref)    (((ref) == LEUART0) || ((ref) == LEUART1))
+#else
+#error Undefined number of low energy UARTs (LEUART).
+#endif
+
+/* Store IRQ id for each UART */
+static uint32_t serial_irq_ids[SERIAL_NUM_UARTS] = { 0 };
+/* Interrupt handler from mbed common */
+static uart_irq_handler irq_handler;
+/* Keep track of incoming DMA IRQ's */
+static bool serial_dma_irq_fired[DMACTRL_CH_CNT] = { false };
+
+/* Serial interface on USBTX/USBRX retargets stdio */
+int stdio_uart_inited = 0;
+serial_t stdio_uart;
+
+static void uart_irq(UARTName, int, SerialIrq);
+uint8_t serial_get_index(serial_t *obj);
+void serial_enable(serial_t *obj, uint8_t enable);
+void serial_enable_pins(serial_t *obj, uint8_t enable);
+IRQn_Type serial_get_rx_irq_index(serial_t *obj);
+IRQn_Type serial_get_tx_irq_index(serial_t *obj);
+CMU_Clock_TypeDef serial_get_clock(serial_t *obj);
+
+/* ISRs for RX and TX events */
+#ifdef UART0
+static void uart0_rx_irq() { uart_irq(UART_0, 0, RxIrq); }
+static void uart0_tx_irq() { uart_irq(UART_0, 0, TxIrq); USART_IntClear((USART_TypeDef*)UART_0, USART_IFC_TXC);}
+#endif
+#ifdef UART1
+static void uart1_rx_irq() { uart_irq(UART_1, 1, RxIrq); }
+static void uart1_tx_irq() { uart_irq(UART_1, 1, TxIrq); USART_IntClear((USART_TypeDef*)UART_1, USART_IFC_TXC);}
+#endif
+#ifdef USART0
+static void usart0_rx_irq() { uart_irq(USART_0, 2, RxIrq); }
+static void usart0_tx_irq() { uart_irq(USART_0, 2, TxIrq); USART_IntClear((USART_TypeDef*)USART_0, USART_IFC_TXC);}
+#endif
+#ifdef USART1
+static void usart1_rx_irq() { uart_irq(USART_1, 3, RxIrq); }
+static void usart1_tx_irq() { uart_irq(USART_1, 3, TxIrq); USART_IntClear((USART_TypeDef*)USART_1, USART_IFC_TXC);}
+#endif
+#ifdef USART2
+static void usart2_rx_irq() { uart_irq(USART_2, 4, RxIrq); }
+static void usart2_tx_irq() { uart_irq(USART_2, 4, TxIrq); USART_IntClear((USART_TypeDef*)USART_2, USART_IFC_TXC);}
+#endif
+#ifdef LEUART0
+static void leuart0_irq()
+{
+    if(LEUART_IntGetEnabled(LEUART0) && (LEUART_IF_RXDATAV | LEUART_IF_FERR | LEUART_IFC_PERR | LEUART_IF_RXOF)) {
+        uart_irq(LEUART_0, 5, RxIrq);
+    } else {
+        uart_irq(LEUART_0, 5, TxIrq);
+    }
+}
+#endif
+#ifdef LEUART1
+static void leuart1_irq()
+{
+    if(LEUART_IntGetEnabled(LEUART1) && (LEUART_IF_RXDATAV | LEUART_IF_FERR | LEUART_IFC_PERR | LEUART_IF_RXOF)) {
+        uart_irq(LEUART_1, 6, RxIrq);
+    } else {
+        uart_irq(LEUART_1, 6, TxIrq);
+    }
+}
+#endif
+
+/**
+ * Initialize the UART using default settings, overridden by settings from serial object
+ *
+ * @param obj pointer to serial object
+ */
+static void uart_init(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        LEUART_Init_TypeDef init = LEUART_INIT_DEFAULT;
+
+        init.enable = leuartDisable;
+        init.baudrate = 9600;
+        init.databits = leuartDatabits8;
+        init.parity = leuartNoParity;
+        init.stopbits = leuartStopbits1;
+#ifdef LEUART_USING_LFXO
+        init.refFreq = LEUART_LF_REF_FREQ;
+#else
+        init.refFreq = LEUART_REF_FREQ;
+#endif
+        LEUART_Init(obj->serial.periph.leuart, &init);
+    } else {
+        USART_InitAsync_TypeDef init = USART_INITASYNC_DEFAULT;
+
+        init.enable = usartDisable;
+        init.baudrate = 9600;
+        init.oversampling = usartOVS16;
+        init.databits = usartDatabits8;
+        init.parity = usartNoParity;
+        init.stopbits = usartStopbits1;
+
+        /* Determine the reference clock, because the correct clock is not set up at init time */
+        init.refFreq = REFERENCE_FREQUENCY;
+
+        USART_InitAsync(obj->serial.periph.uart, &init);
+    }
+}
+
+/**
+* Get index of serial object, relating it to the physical peripheral.
+*
+* @param obj pointer to serial object
+* @return internal index of U(S)ART peripheral
+*/
+inline uint8_t serial_get_index(serial_t *obj)
+{
+    switch ((uint32_t)obj->serial.periph.uart) {
+#ifdef UART0
+        case UART_0:
+            return 0;
+#endif
+#ifdef UART1
+        case UART_1:
+            return 1;
+#endif
+#ifdef USART0
+        case USART_0:
+            return 2;
+#endif
+#ifdef USART1
+        case USART_1:
+            return 3;
+#endif
+#ifdef USART2
+        case USART_2:
+            return 4;
+#endif
+#ifdef LEUART0
+        case LEUART_0:
+            return 5;
+#endif
+#ifdef LEUART1
+        case LEUART_1:
+            return 6;
+#endif
+    }
+    return 0;
+}
+
+/**
+* Get index of serial object RX IRQ, relating it to the physical peripheral.
+*
+* @param obj pointer to serial object
+* @return internal NVIC RX IRQ index of U(S)ART peripheral
+*/
+inline IRQn_Type serial_get_rx_irq_index(serial_t *obj)
+{
+    switch ((uint32_t)obj->serial.periph.uart) {
+#ifdef UART0
+        case UART_0:
+            return UART0_RX_IRQn;
+#endif
+#ifdef UART1
+        case UART_1:
+            return UART1_RX_IRQn;
+#endif
+#ifdef USART0
+        case USART_0:
+            return USART0_RX_IRQn;
+#endif
+#ifdef USART1
+        case USART_1:
+            return USART1_RX_IRQn;
+#endif
+#ifdef USART2
+        case USART_2:
+            return USART2_RX_IRQn;
+#endif
+#ifdef LEUART0
+        case LEUART_0:
+            return LEUART0_IRQn;
+#endif
+#ifdef LEUART1
+        case LEUART_1:
+            return LEUART1_IRQn;
+#endif
+        default:
+            MBED_ASSERT(0);
+    }
+    return (IRQn_Type)0;
+}
+
+/**
+* Get index of serial object TX IRQ, relating it to the physical peripheral.
+*
+* @param obj pointer to serial object
+* @return internal NVIC TX IRQ index of U(S)ART peripheral
+*/
+inline IRQn_Type serial_get_tx_irq_index(serial_t *obj)
+{
+    switch ((uint32_t)obj->serial.periph.uart) {
+#ifdef UART0
+        case UART_0:
+            return UART0_TX_IRQn;
+#endif
+#ifdef UART1
+        case UART_1:
+            return UART1_TX_IRQn;
+#endif
+#ifdef USART0
+        case USART_0:
+            return USART0_TX_IRQn;
+#endif
+#ifdef USART1
+        case USART_1:
+            return USART1_TX_IRQn;
+#endif
+#ifdef USART2
+        case USART_2:
+            return USART2_TX_IRQn;
+#endif
+#ifdef LEUART0
+        case LEUART_0:
+            return LEUART0_IRQn;
+#endif
+#ifdef LEUART1
+        case LEUART_1:
+            return LEUART1_IRQn;
+#endif
+        default:
+            MBED_ASSERT(0);
+    }
+    return (IRQn_Type)0;
+}
+
+/**
+* Get clock tree for serial peripheral pointed to by obj.
+*
+* @param obj pointer to serial object
+* @return CMU_Clock_TypeDef for U(S)ART
+*/
+inline CMU_Clock_TypeDef serial_get_clock(serial_t *obj)
+{
+    switch ((uint32_t)obj->serial.periph.uart) {
+#ifdef UART0
+        case UART_0:
+            return cmuClock_UART0;
+#endif
+#ifdef UART1
+        case UART_1:
+            return cmuClock_UART1;
+#endif
+#ifdef USART0
+        case USART_0:
+            return cmuClock_USART0;
+#endif
+#ifdef USART1
+        case USART_1:
+            return cmuClock_USART1;
+#endif
+#ifdef USART2
+        case USART_2:
+            return cmuClock_USART2;
+#endif
+#ifdef LEUART0
+        case LEUART_0:
+            return cmuClock_LEUART0;
+#endif
+#ifdef LEUART1
+        case LEUART_1:
+            return cmuClock_LEUART1;
+#endif
+        default:
+            return cmuClock_HFPER;
+    }
+}
+
+void serial_preinit(serial_t *obj, PinName tx, PinName rx)
+{
+    /* Get UART object connected to the given pins */
+    UARTName uart_tx = (UARTName) pinmap_peripheral(tx, PinMap_UART_TX);
+    UARTName uart_rx = (UARTName) pinmap_peripheral(rx, PinMap_UART_RX);
+    /* Check that pins are connected to same UART */
+    UARTName uart = (UARTName) pinmap_merge(uart_tx, uart_rx);
+    MBED_ASSERT((int) uart != NC);
+
+    obj->serial.periph.uart = (USART_TypeDef *) uart;
+
+    /* Get location */
+    uint32_t uart_tx_loc = pin_location(tx, PinMap_UART_TX);
+    uint32_t uart_rx_loc = pin_location(rx, PinMap_UART_RX);
+    /* Check that pins are used by same location for the given UART */
+    obj->serial.location = pinmap_merge(uart_tx_loc, uart_rx_loc);
+    MBED_ASSERT(obj->serial.location != (uint32_t)NC);
+
+    /* Store pins in object for easy disabling in serial_free() */
+    obj->serial.rx_pin = rx;
+    obj->serial.tx_pin = tx;
+
+    /* Select interrupt */
+    switch ((uint32_t)obj->serial.periph.uart) {
+#ifdef UART0
+        case UART_0:
+            NVIC_SetVector(UART0_RX_IRQn, (uint32_t) &uart0_rx_irq);
+            NVIC_SetVector(UART0_TX_IRQn, (uint32_t) &uart0_tx_irq);
+            NVIC_SetPriority(UART0_TX_IRQn, 1);
+            break;
+#endif
+#ifdef UART1
+        case UART_1:
+            NVIC_SetVector(UART1_RX_IRQn, (uint32_t) &uart1_rx_irq);
+            NVIC_SetVector(UART1_TX_IRQn, (uint32_t) &uart1_tx_irq);
+            NVIC_SetPriority(UART1_TX_IRQn, 1);
+            break;
+#endif
+#ifdef USART0
+        case USART_0:
+            NVIC_SetVector(USART0_RX_IRQn, (uint32_t) &usart0_rx_irq);
+            NVIC_SetVector(USART0_TX_IRQn, (uint32_t) &usart0_tx_irq);
+            NVIC_SetPriority(USART0_TX_IRQn, 1);
+            break;
+#endif
+#ifdef USART1
+        case USART_1:
+            NVIC_SetVector(USART1_RX_IRQn, (uint32_t) &usart1_rx_irq);
+            NVIC_SetVector(USART1_TX_IRQn, (uint32_t) &usart1_tx_irq);
+            NVIC_SetPriority(USART1_TX_IRQn, 1);
+            break;
+#endif
+#ifdef USART2
+        case USART_2:
+            NVIC_SetVector(USART2_RX_IRQn, (uint32_t) &usart2_rx_irq);
+            NVIC_SetVector(USART2_TX_IRQn, (uint32_t) &usart2_tx_irq);
+            NVIC_SetPriority(USART2_TX_IRQn, 1);
+            break;
+#endif
+#ifdef LEUART0
+        case LEUART_0:
+            NVIC_SetVector(LEUART0_IRQn, (uint32_t) &leuart0_irq);
+            break;
+#endif
+#ifdef LEUART1
+        case LEUART_1:
+            NVIC_SetVector(LEUART1_IRQn, (uint32_t) &leuart1_irq);
+            break;
+#endif
+    }
+}
+
+void serial_enable_pins(serial_t *obj, uint8_t enable)
+{
+    if (enable) {
+        /* Configure GPIO pins*/
+        pin_mode(obj->serial.rx_pin, Input);
+        /* 0x10 sets DOUT. Prevents false start. */
+        pin_mode(obj->serial.tx_pin, PushPull | 0x10);
+    } else {
+        pin_mode(obj->serial.rx_pin, Disabled);
+        pin_mode(obj->serial.tx_pin, Disabled);
+    }
+}
+
+void serial_init(serial_t *obj, PinName tx, PinName rx)
+{
+    serial_preinit(obj, tx, rx);
+
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        // Set up LEUART clock tree
+#ifdef LEUART_USING_LFXO
+        //set to use LFXO
+        CMU_ClockSelectSet(cmuClock_LFB, cmuSelect_LFXO);
+        CMU_ClockEnable(cmuClock_CORELE, true);
+#else
+        //set to use high-speed clock
+        CMU_ClockSelectSet(cmuClock_LFB, cmuSelect_CORELEDIV2);
+#endif
+    }
+
+    CMU_ClockEnable(serial_get_clock(obj), true);
+
+    /* Configure UART for async operation */
+    uart_init(obj);
+
+    /* Limitations of board controller: CDC port only supports 115kbaud */
+    if((tx == STDIO_UART_TX) && (rx == STDIO_UART_RX) && (obj->serial.periph.uart == (USART_TypeDef*)STDIO_UART )) {
+        serial_baud(obj, 115200);
+    }
+
+    /* Enable pins for UART at correct location */
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        obj->serial.periph.leuart->ROUTE = LEUART_ROUTE_RXPEN | LEUART_ROUTE_TXPEN | (obj->serial.location << _LEUART_ROUTE_LOCATION_SHIFT);
+        obj->serial.periph.leuart->IFC = LEUART_IFC_TXC;
+        obj->serial.periph.leuart->CTRL |= LEUART_CTRL_RXDMAWU | LEUART_CTRL_TXDMAWU;
+    } else {
+        obj->serial.periph.uart->ROUTE = USART_ROUTE_RXPEN | USART_ROUTE_TXPEN | (obj->serial.location << _USART_ROUTE_LOCATION_SHIFT);
+        obj->serial.periph.uart->IFC = USART_IFC_TXC;
+    }
+
+    /* If this is the UART to be used for stdio, copy it to the stdio_uart struct */
+    if (obj->serial.periph.uart == (USART_TypeDef*)STDIO_UART ) {
+        stdio_uart_inited = 1;
+        memcpy(&stdio_uart, obj, sizeof(serial_t));
+    }
+
+    serial_enable_pins(obj, true);
+    serial_enable(obj, true);
+
+
+    obj->serial.dmaOptionsTX.dmaChannel = -1;
+    obj->serial.dmaOptionsTX.dmaUsageState = DMA_USAGE_OPPORTUNISTIC;
+
+    obj->serial.dmaOptionsRX.dmaChannel = -1;
+    obj->serial.dmaOptionsRX.dmaUsageState = DMA_USAGE_OPPORTUNISTIC;
+
+}
+
+void serial_enable(serial_t *obj, uint8_t enable)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        if (enable) {
+            LEUART_Enable(obj->serial.periph.leuart, leuartEnable);
+        } else {
+            LEUART_Enable(obj->serial.periph.leuart, leuartDisable);
+        }
+    } else {
+        if (enable) {
+            USART_Enable(obj->serial.periph.uart, usartEnable);
+        } else {
+            USART_Enable(obj->serial.periph.uart, usartDisable);
+        }
+    }
+    serial_irq_ids[serial_get_index(obj)] = 0;
+}
+
+/**
+ * Set UART baud rate
+ */
+void serial_baud(serial_t *obj, int baudrate)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+#ifdef LEUART_USING_LFXO
+
+        /* check if baudrate is within allowed range */
+        MBED_ASSERT(baudrate >= (LEUART_LF_REF_FREQ >> 7));
+
+        if(baudrate > (LEUART_LF_REF_FREQ >> 1)){
+            /* check if baudrate is within allowed range */
+            MBED_ASSERT((baudrate <= (LEUART_HF_REF_FREQ >> 1)) && (baudrate > (LEUART_HF_REF_FREQ >> 10)));
+
+            CMU_ClockSelectSet(cmuClock_LFB, cmuSelect_CORELEDIV2);
+            uint8_t divisor = 1;
+
+            if(baudrate > (LEUART_HF_REF_FREQ >> 7)){
+                divisor = 1;
+            }else if(baudrate > (LEUART_HF_REF_FREQ >> 8)){
+                divisor = 2;
+            }else if(baudrate > (LEUART_HF_REF_FREQ >> 9)){
+                divisor = 4;
+            }else{
+                divisor = 8;
+            }
+            CMU_ClockDivSet(serial_get_clock(obj), divisor);
+            LEUART_BaudrateSet(obj->serial.periph.leuart, LEUART_HF_REF_FREQ/divisor, (uint32_t)baudrate);
+        }else{
+            CMU_ClockSelectSet(cmuClock_LFB, cmuSelect_LFXO);
+            CMU_ClockDivSet(serial_get_clock(obj), 1);
+            LEUART_BaudrateSet(obj->serial.periph.leuart, LEUART_LF_REF_FREQ, (uint32_t)baudrate);
+        }
+#else
+        /* check if baudrate is within allowed range */
+        MBED_ASSERT((baudrate > (LEUART_REF_FREQ >> 10)) && (baudrate <= (LEUART_REF_FREQ >> 1)));
+        uint8_t divisor = 1;
+        if(baudrate > (LEUART_REF_FREQ >> 7)){
+            divisor = 1;
+        }else if(baudrate > (LEUART_REF_FREQ >> 8)){
+            divisor = 2;
+        }else if(baudrate > (LEUART_REF_FREQ >> 9)){
+            divisor = 4;
+        }else{
+            divisor = 8;
+        }
+        CMU_ClockDivSet(serial_get_clock(obj), divisor);
+        LEUART_BaudrateSet(obj->serial.periph.leuart, LEUART_REF_FREQ/divisor, (uint32_t)baudrate);
+#endif
+    } else {
+        USART_BaudrateAsyncSet(obj->serial.periph.uart, REFERENCE_FREQUENCY, (uint32_t)baudrate, usartOVS16);
+    }
+}
+
+/**
+ * Set UART format by re-initializing the peripheral.
+ */
+void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        /* Save the serial state */
+        uint8_t     was_enabled = LEUART_StatusGet(obj->serial.periph.leuart) & (LEUART_STATUS_TXENS | LEUART_STATUS_RXENS);
+        uint32_t    enabled_interrupts = obj->serial.periph.leuart->IEN;
+
+        LEUART_Init_TypeDef init = LEUART_INIT_DEFAULT;
+
+        /* We support 8 data bits ONLY on LEUART*/
+        MBED_ASSERT(data_bits == 8);
+
+        /* Re-init the UART */
+        init.enable = (was_enabled == 0 ? leuartDisable : leuartEnable);
+        init.baudrate = LEUART_BaudrateGet(obj->serial.periph.leuart);
+        if (stop_bits == 2) {
+            init.stopbits = leuartStopbits2;
+        } else {
+            init.stopbits = leuartStopbits1;
+        }
+        switch (parity) {
+            case ParityOdd:
+            case ParityForced0:
+                init.parity = leuartOddParity;
+                break;
+            case ParityEven:
+            case ParityForced1:
+                init.parity = leuartEvenParity;
+                break;
+            default: /* ParityNone */
+                init.parity = leuartNoParity;
+                break;
+        }
+
+        LEUART_Init(obj->serial.periph.leuart, &init);
+
+        /* Re-enable pins for UART at correct location */
+        obj->serial.periph.leuart->ROUTE = LEUART_ROUTE_RXPEN | LEUART_ROUTE_TXPEN | (obj->serial.location << _LEUART_ROUTE_LOCATION_SHIFT);
+
+        /* Re-enable interrupts */
+        if(was_enabled != 0) {
+            obj->serial.periph.leuart->IFC = LEUART_IFC_TXC;
+            obj->serial.periph.leuart->IEN = enabled_interrupts;
+        }
+    } else {
+        /* Save the serial state */
+        uint8_t     was_enabled = USART_StatusGet(obj->serial.periph.uart) & (USART_STATUS_TXENS | USART_STATUS_RXENS);
+        uint32_t    enabled_interrupts = obj->serial.periph.uart->IEN;
+
+
+        USART_InitAsync_TypeDef init = USART_INITASYNC_DEFAULT;
+
+        /* We support 4 to 8 data bits */
+        MBED_ASSERT(data_bits >= 4 && data_bits <= 8);
+
+        /* Re-init the UART */
+        init.enable = (was_enabled == 0 ? usartDisable : usartEnable);
+        init.baudrate = USART_BaudrateGet(obj->serial.periph.uart);
+        init.oversampling = usartOVS16;
+        init.databits = (USART_Databits_TypeDef)((data_bits - 3) << _USART_FRAME_DATABITS_SHIFT);
+        if (stop_bits == 2) {
+            init.stopbits = usartStopbits2;
+        } else {
+            init.stopbits = usartStopbits1;
+        }
+        switch (parity) {
+            case ParityOdd:
+            case ParityForced0:
+                init.parity = usartOddParity;
+                break;
+            case ParityEven:
+            case ParityForced1:
+                init.parity = usartEvenParity;
+                break;
+            default: /* ParityNone */
+                init.parity = usartNoParity;
+                break;
+        }
+
+        USART_InitAsync(obj->serial.periph.uart, &init);
+
+        /* Re-enable pins for UART at correct location */
+        obj->serial.periph.uart->ROUTE = USART_ROUTE_RXPEN | USART_ROUTE_TXPEN | (obj->serial.location << _USART_ROUTE_LOCATION_SHIFT);
+
+        /* Re-enable interrupts */
+        if(was_enabled != 0) {
+            obj->serial.periph.uart->IFC = USART_IFC_TXC;
+            obj->serial.periph.uart->IEN = enabled_interrupts;
+        }
+    }
+}
+
+/******************************************************************************
+ *                               INTERRUPTS                                   *
+ ******************************************************************************/
+uint8_t serial_tx_ready(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        return (obj->serial.periph.leuart->STATUS & LEUART_STATUS_TXBL) ? true : false;
+    } else {
+        return (obj->serial.periph.uart->STATUS & USART_STATUS_TXBL) ? true : false;
+    }
+}
+
+uint8_t serial_rx_ready(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        return (obj->serial.periph.leuart->STATUS & LEUART_STATUS_RXDATAV) ? true : false;
+    } else {
+        return (obj->serial.periph.uart->STATUS & USART_STATUS_RXDATAV) ? true : false;
+    }
+}
+
+void serial_write_asynch(serial_t *obj, int data)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        obj->serial.periph.leuart->TXDATA = (uint32_t)data;
+    } else {
+        obj->serial.periph.uart->TXDATA = (uint32_t)data;
+    }
+}
+
+int serial_read_asynch(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        return (int)obj->serial.periph.leuart->RXDATA;
+    } else {
+        return (int)obj->serial.periph.uart->RXDATA;
+    }
+}
+
+uint8_t serial_tx_int_flag(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        return (obj->serial.periph.leuart->IF & LEUART_IF_TXBL) ? true : false;
+    } else {
+        return (obj->serial.periph.uart->IF & USART_IF_TXBL) ? true : false;
+    }
+}
+
+uint8_t serial_rx_int_flag(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        return (obj->serial.periph.leuart->IF & LEUART_IF_RXDATAV) ? true : false;
+    } else {
+        return (obj->serial.periph.uart->IF & USART_IF_RXDATAV) ? true : false;
+    }
+}
+
+void serial_read_asynch_complete(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        obj->serial.periph.leuart->IFC |= LEUART_IFC_RXOF; // in case it got full
+    } else {
+        obj->serial.periph.uart->IFC |= USART_IFC_RXFULL; // in case it got full
+    }
+}
+
+void serial_write_asynch_complete(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        obj->serial.periph.leuart->IFC |= LEUART_IFC_TXC;
+    } else {
+        obj->serial.periph.uart->IFC |= USART_IFC_TXC;
+    }
+}
+
+/** Enable and set the interrupt handler for write (TX)
+ *
+ * @param obj     The serial object
+ * @param address The address of TX handler
+ * @param enable  Set to non-zero to enable or zero to disable
+ */
+void serial_write_enable_interrupt(serial_t *obj, uint32_t address, uint8_t enable)
+{
+    NVIC_SetVector(serial_get_tx_irq_index(obj), address);
+    serial_irq_set(obj, (SerialIrq)1, enable);
+}
+
+/** Enable and set the interrupt handler for read (RX)
+ *
+ * @param obj     The serial object
+ * @param address The address of RX handler
+ * @param enable  Set to non-zero to enable or zero to disable
+ */
+void serial_read_enable_interrupt(serial_t *obj, uint32_t address, uint8_t enable)
+{
+    NVIC_SetVector(serial_get_rx_irq_index(obj), address);
+    serial_irq_set(obj, (SerialIrq)0, enable);
+}
+
+uint8_t serial_interrupt_enabled(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        return (obj->serial.periph.leuart->IEN & (LEUART_IEN_RXDATAV | LEUART_IEN_TXBL)) ? true : false;
+    } else {
+        return (obj->serial.periph.uart->IEN & (USART_IEN_RXDATAV | USART_IEN_TXBL)) ? true : false;
+    }
+}
+
+/**
+ * Set handler for all serial interrupts (is probably SerialBase::_handler())
+ * and store IRQ ID to be returned to the handler upon interrupt. ID is
+ * probably a pointer to the calling Serial object.
+ */
+void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id)
+{
+    irq_handler = handler;
+    serial_irq_ids[serial_get_index(obj)] = id;
+}
+
+/**
+ * Generic ISR for all UARTs, both TX and RX
+ */
+static void uart_irq(UARTName name, int index, SerialIrq irq)
+{
+    if (serial_irq_ids[index] != 0) {
+        /* Pass interrupt on to mbed common handler */
+        irq_handler(serial_irq_ids[index], irq);
+        /* Clearing interrupt not necessary */
+    }
+}
+
+/**
+ * Set ISR for a given UART and interrupt event (TX or RX)
+ */
+void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        /* Enable or disable interrupt */
+        if (enable) {
+            if (irq == RxIrq) { /* RX */
+                obj->serial.periph.leuart->IEN |= LEUART_IEN_RXDATAV;
+                NVIC_ClearPendingIRQ(serial_get_rx_irq_index(obj));
+                NVIC_EnableIRQ(serial_get_rx_irq_index(obj));
+            } else { /* TX */
+                obj->serial.periph.leuart->IEN |= LEUART_IEN_TXC;
+                NVIC_ClearPendingIRQ(serial_get_tx_irq_index(obj));
+                NVIC_SetPriority(serial_get_tx_irq_index(obj), 1);
+                NVIC_EnableIRQ(serial_get_tx_irq_index(obj));
+            }
+        } else {
+            if (irq == RxIrq) { /* RX */
+                obj->serial.periph.leuart->IEN &= ~LEUART_IEN_RXDATAV;
+                NVIC_DisableIRQ(serial_get_rx_irq_index(obj));
+            } else { /* TX */
+                obj->serial.periph.leuart->IEN &= ~LEUART_IEN_TXC;
+                NVIC_DisableIRQ(serial_get_tx_irq_index(obj));
+            }
+        }
+    } else {
+        /* Enable or disable interrupt */
+        if (enable) {
+            if (irq == RxIrq) { /* RX */
+                obj->serial.periph.uart->IEN |= USART_IEN_RXDATAV;
+                NVIC_ClearPendingIRQ(serial_get_rx_irq_index(obj));
+                NVIC_EnableIRQ(serial_get_rx_irq_index(obj));
+            } else { /* TX */
+                obj->serial.periph.uart->IEN |= USART_IEN_TXC;
+                NVIC_ClearPendingIRQ(serial_get_tx_irq_index(obj));
+                NVIC_SetPriority(serial_get_tx_irq_index(obj), 1);
+                NVIC_EnableIRQ(serial_get_tx_irq_index(obj));
+            }
+        } else {
+            if (irq == RxIrq) { /* RX */
+                obj->serial.periph.uart->IEN &= ~USART_IEN_RXDATAV;
+                NVIC_DisableIRQ(serial_get_rx_irq_index(obj));
+            } else { /* TX */
+                obj->serial.periph.uart->IEN &= ~USART_IEN_TXC;
+                NVIC_DisableIRQ(serial_get_tx_irq_index(obj));
+            }
+        }
+    }
+}
+
+/******************************************************************************
+ *                               READ/WRITE                                   *
+ ******************************************************************************/
+
+/**
+ *  Get one char from serial link
+ */
+int serial_getc(serial_t *obj)
+{
+    /* Emlib USART_Rx blocks until data is available, so we don't need to use
+     * serial_readable(). Use USART_RxDataGet() to read register directly. */
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        return LEUART_Rx(obj->serial.periph.leuart);
+    } else {
+        return USART_Rx(obj->serial.periph.uart);
+    }
+}
+
+/*
+ * Send one char over serial link
+ */
+void serial_putc(serial_t *obj, int c)
+{
+    /* Emlib USART_Tx blocks until buffer is writable (non-full), so we don't
+     * need to use serial_writable(). */
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        LEUART_Tx(obj->serial.periph.leuart, (uint8_t)(c));
+    } else {
+        USART_Tx(obj->serial.periph.uart, (uint8_t)(c));
+    }
+}
+
+/**
+ * Check if data is available in RX data vector
+ */
+int serial_readable(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        return obj->serial.periph.leuart->STATUS & LEUART_STATUS_RXDATAV;
+    } else {
+        return obj->serial.periph.uart->STATUS & USART_STATUS_RXDATAV;
+    }
+}
+
+/**
+ * Check if TX buffer is empty
+ */
+int serial_writable(serial_t *obj)
+{
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        return obj->serial.periph.leuart->STATUS & LEUART_STATUS_TXBL;
+    } else {
+        return obj->serial.periph.uart->STATUS & USART_STATUS_TXBL;
+    }
+}
+
+/**
+ * Clear UART interrupts
+ */
+void serial_clear(serial_t *obj)
+{
+    /* Interrupts automatically clear when condition is not met anymore */
+}
+
+void serial_break_set(serial_t *obj)
+{
+    /* Send transmission break */
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        obj->serial.periph.leuart->TXDATAX = LEUART_TXDATAX_TXBREAK;
+    } else {
+        obj->serial.periph.uart->TXDATAX = USART_TXDATAX_TXBREAK;
+    }
+}
+
+void serial_break_clear(serial_t *obj)
+{
+    /* No need to clear break, it is automatically cleared after one frame.
+     * From the reference manual:
+     *
+     * By setting TXBREAK, the output will be held low during the stop-bit
+     * period to generate a framing error. A receiver that supports break
+     * detection detects this state, allowing it to be used e.g. for framing
+     * of larger data packets. The line is driven high before the next frame
+     * is transmitted so the next start condition can be identified correctly
+     * by the recipient. Continuous breaks lasting longer than a USART frame
+     * are thus not supported by the USART. GPIO can be used for this.
+     */
+}
+
+void serial_pinout_tx(PinName tx)
+{
+    /* 0x10 sets DOUT high. Prevents false start. */
+    pin_mode(tx, PushPull | 0x10);
+}
+
+/************************************************************************************
+ *          DMA helper functions                                                    *
+ ************************************************************************************/
+/******************************************
+* static void serial_dmaTransferComplete(uint channel, bool primary, void* user)
+*
+* Callback function which gets called upon DMA transfer completion
+* the user-defined pointer is pointing to the CPP-land thunk
+******************************************/
+static void serial_dmaTransferComplete(unsigned int channel, bool primary, void *user)
+{
+    /* Store information about which channel triggered because CPP doesn't take arguments */
+    serial_dma_irq_fired[channel] = true;
+
+    /* User pointer should be a thunk to CPP land */
+    if (user != NULL) {
+        ((DMACallback)user)();
+    }
+}
+
+/******************************************
+* static void serial_setupDmaChannel(serial_t *obj, bool tx_nrx)
+*
+* Sets up the DMA configuration block for the assigned channel
+* tx_nrx: true if configuring TX, false if configuring RX.
+******************************************/
+static void serial_dmaSetupChannel(serial_t *obj, bool tx_nrx)
+{
+    DMA_CfgChannel_TypeDef  channelConfig;
+
+    if(tx_nrx) {
+        //setup TX channel
+        channelConfig.highPri = false;
+        channelConfig.enableInt = true;
+        channelConfig.cb = &(obj->serial.dmaOptionsTX.dmaCallback);
+
+        switch((uint32_t)(obj->serial.periph.uart)) {
+#ifdef UART0
+            case UART_0:
+                channelConfig.select = DMAREQ_UART0_TXBL;
+                break;
+#endif
+#ifdef UART1
+            case UART_1:
+                channelConfig.select = DMAREQ_UART1_TXBL;
+                break;
+#endif
+#ifdef USART0
+            case USART_0:
+                channelConfig.select = DMAREQ_USART0_TXBL;
+                break;
+#endif
+#ifdef USART1
+            case USART_1:
+                channelConfig.select = DMAREQ_USART1_TXBL;
+                break;
+#endif
+#ifdef USART2
+            case USART_2:
+                channelConfig.select = DMAREQ_USART2_TXBL;
+                break;
+#endif
+#ifdef LEUART0
+            case LEUART_0:
+                channelConfig.select = DMAREQ_LEUART0_TXBL;
+                break;
+#endif
+#ifdef LEUART1
+            case LEUART_1:
+                channelConfig.select = DMAREQ_LEUART1_TXBL;
+                break;
+#endif
+        }
+
+        DMA_CfgChannel(obj->serial.dmaOptionsTX.dmaChannel, &channelConfig);
+    } else {
+        //setup RX channel
+        channelConfig.highPri = true;
+        channelConfig.enableInt = true;
+        channelConfig.cb = &(obj->serial.dmaOptionsRX.dmaCallback);
+
+        switch((uint32_t)(obj->serial.periph.uart)) {
+#ifdef UART0
+            case UART_0:
+                channelConfig.select = DMAREQ_UART0_RXDATAV;
+                break;
+#endif
+#ifdef UART1
+            case UART_1:
+                channelConfig.select = DMAREQ_UART1_RXDATAV;
+                break;
+#endif
+#ifdef USART0
+            case USART_0:
+                channelConfig.select = DMAREQ_USART0_RXDATAV;
+                break;
+#endif
+#ifdef USART1
+            case USART_1:
+                channelConfig.select = DMAREQ_USART1_RXDATAV;
+                break;
+#endif
+#ifdef USART2
+            case USART_2:
+                channelConfig.select = DMAREQ_USART2_RXDATAV;
+                break;
+#endif
+#ifdef LEUART0
+            case LEUART_0:
+                channelConfig.select = DMAREQ_LEUART0_RXDATAV;
+                break;
+#endif
+#ifdef LEUART1
+            case LEUART_1:
+                channelConfig.select = DMAREQ_LEUART1_RXDATAV;
+                break;
+#endif
+        }
+
+        DMA_CfgChannel(obj->serial.dmaOptionsRX.dmaChannel, &channelConfig);
+    }
+
+
+}
+
+/******************************************
+* static void serial_dmaTrySetState(DMA_OPTIONS_t *obj, DMAUsage requestedState)
+*
+* Tries to set the passed DMA state to the requested state.
+*
+* requested state possibilities:
+*   * NEVER:
+*       if the previous state was always, will deallocate the channel
+*   * OPPORTUNISTIC:
+*       If the previous state was always, will reuse that channel but free upon next completion.
+*       If not, will try to acquire a channel.
+*       When allocated, state changes to DMA_USAGE_TEMPORARY_ALLOCATED.
+*   * ALWAYS:
+*       Will try to allocate a channel and keep it.
+*       If succesfully allocated, state changes to DMA_USAGE_ALLOCATED.
+******************************************/
+static void serial_dmaTrySetState(DMA_OPTIONS_t *obj, DMAUsage requestedState, serial_t *serialPtr, bool tx_nrx)
+{
+    DMAUsage currentState = obj->dmaUsageState;
+    int tempDMAChannel = -1;
+
+    if ((requestedState == DMA_USAGE_ALWAYS) && (currentState != DMA_USAGE_ALLOCATED)) {
+        /* Try to allocate channel */
+        tempDMAChannel = dma_channel_allocate(DMA_CAP_NONE);
+        if(tempDMAChannel >= 0) {
+            obj->dmaChannel = tempDMAChannel;
+            obj->dmaUsageState = DMA_USAGE_ALLOCATED;
+            dma_init();
+            serial_dmaSetupChannel(serialPtr, tx_nrx);
+        }
+    } else if (requestedState == DMA_USAGE_OPPORTUNISTIC) {
+        if (currentState == DMA_USAGE_ALLOCATED) {
+            /* Channels have already been allocated previously by an ALWAYS state, so after this transfer, we will release them */
+            obj->dmaUsageState = DMA_USAGE_TEMPORARY_ALLOCATED;
+        } else {
+            /* Try to allocate channel */
+            tempDMAChannel = dma_channel_allocate(DMA_CAP_NONE);
+            if(tempDMAChannel >= 0) {
+                obj->dmaChannel = tempDMAChannel;
+                obj->dmaUsageState = DMA_USAGE_TEMPORARY_ALLOCATED;
+                dma_init();
+                serial_dmaSetupChannel(serialPtr, tx_nrx);
+            }
+        }
+    } else if (requestedState == DMA_USAGE_NEVER) {
+        /* If channel is allocated, get rid of it */
+        dma_channel_free(obj->dmaChannel);
+        obj->dmaChannel = -1;
+        obj->dmaUsageState = DMA_USAGE_NEVER;
+    }
+}
+
+static void serial_dmaActivate(serial_t *obj, void* cb, void* buffer, int length, bool tx_nrx)
+{
+    DMA_CfgDescr_TypeDef channelConfig;
+
+    if(tx_nrx) {
+        // Set DMA callback
+        obj->serial.dmaOptionsTX.dmaCallback.cbFunc = serial_dmaTransferComplete;
+        obj->serial.dmaOptionsTX.dmaCallback.userPtr = cb;
+
+        // Set up configuration structure
+        channelConfig.dstInc = dmaDataIncNone;
+        channelConfig.srcInc = dmaDataInc1;
+        channelConfig.size = dmaDataSize1;
+        channelConfig.arbRate = dmaArbitrate1;
+        channelConfig.hprot = 0;
+
+        DMA_CfgDescr(obj->serial.dmaOptionsTX.dmaChannel, true, &channelConfig);
+        if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+            // Activate TX
+            obj->serial.periph.leuart->CMD = LEUART_CMD_TXEN;
+            while(obj->serial.periph.leuart->SYNCBUSY & LEUART_SYNCBUSY_CMD);
+
+            // Kick off TX DMA
+            DMA_ActivateBasic(obj->serial.dmaOptionsTX.dmaChannel, true, false, (void*) &(obj->serial.periph.leuart->TXDATA), buffer, length - 1);
+        } else {
+            // Activate TX amd clear TX buffer
+            obj->serial.periph.uart->CMD = USART_CMD_TXEN | USART_CMD_CLEARTX;
+
+            // Kick off TX DMA
+            DMA_ActivateBasic(obj->serial.dmaOptionsTX.dmaChannel, true, false, (void*) &(obj->serial.periph.uart->TXDATA), buffer, length - 1);
+        }
+    } else {
+        // Set DMA callback
+        obj->serial.dmaOptionsRX.dmaCallback.cbFunc = serial_dmaTransferComplete;
+        obj->serial.dmaOptionsRX.dmaCallback.userPtr = cb;
+
+        // Set up configuration structure
+        channelConfig.dstInc = dmaDataInc1;
+        channelConfig.srcInc = dmaDataIncNone;
+        channelConfig.size = dmaDataSize1;
+        channelConfig.arbRate = dmaArbitrate1;
+        channelConfig.hprot = 0;
+
+        DMA_CfgDescr(obj->serial.dmaOptionsRX.dmaChannel, true, &channelConfig);
+
+        if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+            // Activate RX and clear RX buffer
+            obj->serial.periph.leuart->CMD = LEUART_CMD_RXEN | LEUART_CMD_CLEARRX;
+            while(obj->serial.periph.leuart->SYNCBUSY & LEUART_SYNCBUSY_CMD);
+
+            // Kick off RX DMA
+            DMA_ActivateBasic(obj->serial.dmaOptionsRX.dmaChannel, true, false, buffer, (void*) &(obj->serial.periph.leuart->RXDATA), length - 1);
+        } else {
+            // Activate RX and clear RX buffer
+            obj->serial.periph.uart->CMD = USART_CMD_RXEN | USART_CMD_CLEARRX;
+
+            // Kick off RX DMA
+            DMA_ActivateBasic(obj->serial.dmaOptionsRX.dmaChannel, true, false, buffer, (void*) &(obj->serial.periph.uart->RXDATA), length - 1);
+        }
+    }
+}
+
+/************************************************************************************
+ *          ASYNCHRONOUS HAL                                                        *
+ ************************************************************************************/
+
+#if DEVICE_SERIAL_ASYNCH
+
+/************************************
+ * HELPER FUNCTIONS                 *
+ ***********************************/
+
+/** Configure TX events
+ *
+ * @param obj    The serial object
+ * @param event  The logical OR of the TX events to configure
+ * @param enable Set to non-zero to enable events, or zero to disable them
+ */
+void serial_tx_enable_event(serial_t *obj, int event, uint8_t enable)
+{
+    // Shouldn't have to enable TX interrupt here, just need to keep track of the requested events.
+    if(enable) obj->serial.events |= event;
+    else obj->serial.events &= ~event;
+}
+
+/**
+ * @param obj    The serial object.
+ * @param event  The logical OR of the RX events to configure
+ * @param enable Set to non-zero to enable events, or zero to disable them
+ */
+void serial_rx_enable_event(serial_t *obj, int event, uint8_t enable)
+{
+    if(enable) {
+        obj->serial.events |= event;
+    } else {
+        obj->serial.events &= ~event;
+    }
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        if(event & SERIAL_EVENT_RX_FRAMING_ERROR) {
+            //FERR interrupt source
+            if(enable) obj->serial.periph.leuart->IEN |= LEUART_IEN_FERR;
+            else obj->serial.periph.leuart->IEN &= ~LEUART_IEN_FERR;
+        }
+        if(event & SERIAL_EVENT_RX_PARITY_ERROR) {
+            //PERR interrupt source
+            if(enable) obj->serial.periph.leuart->IEN |= LEUART_IEN_PERR;
+            else obj->serial.periph.leuart->IEN &= ~LEUART_IEN_PERR;
+        }
+        if(event & SERIAL_EVENT_RX_OVERFLOW) {
+            //RXOF interrupt source
+            if(enable) obj->serial.periph.leuart->IEN |= LEUART_IEN_RXOF;
+            else obj->serial.periph.leuart->IEN &= ~LEUART_IEN_RXOF;
+        }
+    } else {
+        if(event & SERIAL_EVENT_RX_FRAMING_ERROR) {
+            //FERR interrupt source
+            if(enable) obj->serial.periph.uart->IEN |= USART_IEN_FERR;
+            else obj->serial.periph.uart->IEN &= ~USART_IEN_FERR;
+        }
+        if(event & SERIAL_EVENT_RX_PARITY_ERROR) {
+            //PERR interrupt source
+            if(enable) obj->serial.periph.uart->IEN |= USART_IEN_PERR;
+            else obj->serial.periph.uart->IEN &= ~USART_IEN_PERR;
+        }
+        if(event & SERIAL_EVENT_RX_OVERFLOW) {
+            //RXOF interrupt source
+            if(enable) obj->serial.periph.uart->IEN |= USART_IEN_RXOF;
+            else obj->serial.periph.uart->IEN &= ~USART_IEN_RXOF;
+        }
+    }
+}
+
+/** Configure the TX buffer for an asynchronous write serial transaction
+ *
+ * @param obj       The serial object.
+ * @param tx        The buffer for sending.
+ * @param tx_length The number of words to transmit.
+ */
+void serial_tx_buffer_set(serial_t *obj, void *tx, int tx_length, uint8_t width)
+{
+    // We only support byte buffers for now
+    MBED_ASSERT(width == 8);
+
+    if(serial_tx_active(obj)) return;
+
+    obj->tx_buff.buffer = tx;
+    obj->tx_buff.length = tx_length;
+    obj->tx_buff.pos = 0;
+
+    return;
+}
+
+/** Configure the TX buffer for an asynchronous read serial transaction
+ *
+ * @param obj       The serial object.
+ * @param rx        The buffer for receiving.
+ * @param rx_length The number of words to read.
+ */
+void serial_rx_buffer_set(serial_t *obj, void *rx, int rx_length, uint8_t width)
+{
+    // We only support byte buffers for now
+    MBED_ASSERT(width == 8);
+
+    if(serial_rx_active(obj)) return;
+
+    obj->rx_buff.buffer = rx;
+    obj->rx_buff.length = rx_length;
+    obj->rx_buff.pos = 0;
+
+    return;
+}
+
+/************************************
+ * TRANSFER FUNCTIONS               *
+ ***********************************/
+
+/** Begin asynchronous TX transfer. The used buffer is specified in the serial object,
+ *  tx_buff
+ *
+ * @param obj  The serial object
+ * @param cb   The function to call when an event occurs
+ * @param hint A suggestion for how to use DMA with this transfer
+ * @return Returns number of data transfered, or 0 otherwise
+ */
+int serial_tx_asynch(serial_t *obj, const void *tx, size_t tx_length, uint8_t tx_width, uint32_t handler, uint32_t event, DMAUsage hint)
+{
+    // Check that a buffer has indeed been set up
+    MBED_ASSERT(tx != (void*)0);
+    if(tx_length == 0) return 0;
+
+    // Set up buffer
+    serial_tx_buffer_set(obj, (void *)tx, tx_length, tx_width);
+
+    // Set up events
+    serial_tx_enable_event(obj, SERIAL_EVENT_TX_ALL, false);
+    serial_tx_enable_event(obj, event, true);
+
+    // Set up sleepmode
+#ifdef LEUART_USING_LFXO
+    if(LEUART_REF_VALID(obj->serial.periph.leuart) && (LEUART_BaudrateGet(obj->serial.periph.leuart) <= (LEUART_LF_REF_FREQ/2))){
+        blockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE_LEUART);
+    }else{
+        blockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE);
+    }
+#else
+    blockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE);
+#endif
+
+    // Determine DMA strategy
+    serial_dmaTrySetState(&(obj->serial.dmaOptionsTX), hint, obj, true);
+
+    // If DMA, kick off DMA transfer
+    if(obj->serial.dmaOptionsTX.dmaChannel >= 0) {
+        serial_dmaActivate(obj, (void*)handler, obj->tx_buff.buffer, obj->tx_buff.length, true);
+    }
+    // Else, activate interrupt. TXBL will take care of buffer filling through ISR.
+    else {
+        // Store callback
+        NVIC_ClearPendingIRQ(serial_get_tx_irq_index(obj));
+        NVIC_DisableIRQ(serial_get_tx_irq_index(obj));
+        NVIC_SetPriority(serial_get_tx_irq_index(obj), 1);
+        NVIC_SetVector(serial_get_tx_irq_index(obj), (uint32_t)handler);
+        NVIC_EnableIRQ(serial_get_tx_irq_index(obj));
+
+        if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+            // Activate TX and clear TX buffer
+            obj->serial.periph.leuart->CMD = LEUART_CMD_TXEN | LEUART_CMD_CLEARTX;
+            while(obj->serial.periph.leuart->SYNCBUSY & LEUART_SYNCBUSY_CMD);
+
+            // Enable interrupt
+            LEUART_IntEnable(obj->serial.periph.leuart, LEUART_IEN_TXBL);
+        } else {
+            // Activate TX and clear TX buffer
+            obj->serial.periph.uart->CMD = USART_CMD_TXEN | USART_CMD_CLEARTX;
+
+            // Enable interrupt
+            USART_IntEnable(obj->serial.periph.uart, USART_IEN_TXBL);
+        }
+    }
+
+    return 0;
+}
+
+/** Begin asynchronous RX transfer (enable interrupt for data collecting)
+ *  The used buffer is specified in the serial object - rx_buff
+ *
+ * @param obj  The serial object
+ * @param cb   The function to call when an event occurs
+ * @param hint A suggestion for how to use DMA with this transfer
+ */
+void serial_rx_asynch(serial_t *obj, void *rx, size_t rx_length, uint8_t rx_width, uint32_t handler, uint32_t event, uint8_t char_match, DMAUsage hint)
+{
+    // Check that a buffer has indeed been set up
+    MBED_ASSERT(rx != (void*)0);
+    if(rx_length == 0) return;
+
+    // Set up buffer
+    serial_rx_buffer_set(obj,(void*) rx, rx_length, rx_width);
+
+    //disable character match if no character is specified
+    if(char_match == SERIAL_RESERVED_CHAR_MATCH){
+        event &= ~SERIAL_EVENT_RX_CHARACTER_MATCH;
+    }
+
+    /*clear all set interrupts*/
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        LEUART_IntClear(obj->serial.periph.leuart, LEUART_IFC_PERR | LEUART_IFC_FERR | LEUART_IFC_RXOF);
+    }else{
+        USART_IntClear(obj->serial.periph.uart,  USART_IFC_PERR | USART_IFC_FERR | USART_IFC_RXOF);
+    }
+
+    // Set up events
+    serial_rx_enable_event(obj, SERIAL_EVENT_RX_ALL, false);
+    serial_rx_enable_event(obj, event, true);
+    obj->char_match = char_match;
+
+    // Set up sleepmode
+#ifdef LEUART_USING_LFXO
+    if(LEUART_REF_VALID(obj->serial.periph.leuart) && (LEUART_BaudrateGet(obj->serial.periph.leuart) <= (LEUART_LF_REF_FREQ/2))){
+        blockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE_LEUART);
+    }else{
+        blockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE);
+    }
+#else
+    blockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE);
+#endif
+
+    // Determine DMA strategy
+    // If character match is enabled, we can't use DMA, sadly. We could when using LEUART though, but that support is not in here yet.
+    // TODO: add DMA support for character matching with leuart
+    if(!(event & SERIAL_EVENT_RX_CHARACTER_MATCH)) {
+        serial_dmaTrySetState(&(obj->serial.dmaOptionsRX), hint, obj, false);
+    }else{
+        serial_dmaTrySetState(&(obj->serial.dmaOptionsRX), DMA_USAGE_NEVER, obj, false);
+    }
+
+    // If DMA, kick off DMA
+    if(obj->serial.dmaOptionsRX.dmaChannel >= 0) {
+        serial_dmaActivate(obj, (void*)handler, obj->rx_buff.buffer, obj->rx_buff.length, false);
+    }
+    // Else, activate interrupt. RXDATAV is responsible for incoming data notification.
+    else {
+        // Store callback
+        NVIC_ClearPendingIRQ(serial_get_rx_irq_index(obj));
+        NVIC_SetVector(serial_get_rx_irq_index(obj), (uint32_t)handler);
+        NVIC_EnableIRQ(serial_get_rx_irq_index(obj));
+
+        if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+            // Activate RX and clear RX buffer
+            obj->serial.periph.leuart->CMD = LEUART_CMD_RXEN | LEUART_CMD_CLEARRX;
+            while(obj->serial.periph.leuart->SYNCBUSY & LEUART_SYNCBUSY_CMD);
+
+            // Enable interrupt
+            LEUART_IntEnable(obj->serial.periph.leuart, LEUART_IEN_RXDATAV);
+        } else {
+            // Activate RX and clear RX buffer
+            obj->serial.periph.uart->CMD = USART_CMD_RXEN | USART_CMD_CLEARRX;
+
+            // Clear RXFULL
+            USART_IntClear(obj->serial.periph.uart, USART_IFC_RXFULL);
+
+            // Enable interrupt
+            USART_IntEnable(obj->serial.periph.uart, USART_IEN_RXDATAV);
+        }
+    }
+
+    return;
+}
+
+/** Attempts to determine if the serial peripheral is already in use for TX
+ *
+ * @param obj The serial object
+ * @return Non-zero if the TX transaction is ongoing, 0 otherwise
+ */
+uint8_t serial_tx_active(serial_t *obj)
+{
+    switch(obj->serial.dmaOptionsTX.dmaUsageState) {
+        case DMA_USAGE_TEMPORARY_ALLOCATED:
+            /* Temporary allocation always means its active, as this state gets cleared afterwards */
+            return 1;
+        case DMA_USAGE_ALLOCATED:
+            /* Check whether the allocated DMA channel is active by checking the DMA transfer */
+            return(DMA_ChannelEnabled(obj->serial.dmaOptionsTX.dmaChannel));
+        default:
+            /* Check whether interrupt for serial TX is enabled */
+            if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+                return (obj->serial.periph.leuart->IEN & (LEUART_IEN_TXBL)) ? true : false;
+            } else {
+                return (obj->serial.periph.uart->IEN & (USART_IEN_TXBL)) ? true : false;
+            }
+    }
+}
+
+/** Attempts to determine if the serial peripheral is already in use for RX
+ *
+ * @param obj The serial object
+ * @return Non-zero if the RX transaction is ongoing, 0 otherwise
+ */
+uint8_t serial_rx_active(serial_t *obj)
+{
+    switch(obj->serial.dmaOptionsRX.dmaUsageState) {
+        case DMA_USAGE_TEMPORARY_ALLOCATED:
+            /* Temporary allocation always means its active, as this state gets cleared afterwards */
+            return 1;
+        case DMA_USAGE_ALLOCATED:
+            /* Check whether the allocated DMA channel is active by checking the DMA transfer */
+            return(DMA_ChannelEnabled(obj->serial.dmaOptionsRX.dmaChannel));
+        default:
+            /* Check whether interrupt for serial TX is enabled */
+            if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+                return (obj->serial.periph.leuart->IEN & (LEUART_IEN_RXDATAV)) ? true : false;
+            } else {
+                return (obj->serial.periph.uart->IEN & (USART_IEN_RXDATAV)) ? true : false;
+            }
+    }
+}
+
+/** The asynchronous TX handler. Writes to the TX FIFO and checks for events.
+ *  If any TX event has occured, the TX abort function is called.
+ *
+ * @param obj The serial object
+ * @return Returns event flags if a TX transfer termination condition was met or 0 otherwise
+ */
+int serial_tx_irq_handler_asynch(serial_t *obj)
+{
+    /* This interrupt handler is called from USART irq */
+    uint8_t *buf = obj->tx_buff.buffer;
+
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        if(obj->serial.periph.leuart->IEN & LEUART_IEN_TXBL){
+            /* There is still data to send */
+            while((LEUART_StatusGet(obj->serial.periph.leuart) & LEUART_STATUS_TXBL) && (obj->tx_buff.pos <= (obj->tx_buff.length - 1))) {
+                while (obj->serial.periph.leuart->SYNCBUSY);
+                LEUART_Tx(obj->serial.periph.leuart, buf[obj->tx_buff.pos]);
+                obj->tx_buff.pos++;
+            }
+            if(obj->tx_buff.pos >= obj->tx_buff.length){
+                /* Last byte has been put in TX, set up TXC interrupt */
+                LEUART_IntDisable(obj->serial.periph.leuart, LEUART_IEN_TXBL);
+                LEUART_IntEnable(obj->serial.periph.leuart, LEUART_IEN_TXC);
+            }
+        }else if (obj->serial.periph.leuart->IF & LEUART_IF_TXC){
+            /* Last byte has been successfully transmitted. Stop the procedure */
+            serial_tx_abort_asynch(obj);
+            return SERIAL_EVENT_TX_COMPLETE & obj->serial.events;
+        }
+    } else {
+        if(obj->serial.periph.uart->IEN & USART_IEN_TXBL){
+            /* There is still data to send */
+            while((USART_StatusGet(obj->serial.periph.uart) & USART_STATUS_TXBL) && (obj->tx_buff.pos <= (obj->tx_buff.length - 1))) {
+                USART_Tx(obj->serial.periph.uart, buf[obj->tx_buff.pos]);
+                obj->tx_buff.pos++;
+            }
+            if(obj->tx_buff.pos >= obj->tx_buff.length){
+                /* Last byte has been put in TX, set up TXC interrupt */
+                USART_IntDisable(obj->serial.periph.uart, USART_IEN_TXBL);
+                USART_IntEnable(obj->serial.periph.uart, USART_IEN_TXC);
+            }
+        } else if (obj->serial.periph.uart->IF & USART_IF_TXC) {
+            /* Last byte has been successfully transmitted. Stop the procedure */
+            serial_tx_abort_asynch(obj);
+            return SERIAL_EVENT_TX_COMPLETE & obj->serial.events;
+        }
+    }
+    return 0;
+}
+
+/** The asynchronous RX handler. Reads from the RX FIFOF and checks for events.
+ *  If any RX event has occured, the RX abort function is called.
+ *
+ * @param obj The serial object
+ * @return Returns event flags if a RX transfer termination condition was met or 0 otherwise
+ */
+int serial_rx_irq_handler_asynch(serial_t *obj)
+{
+    int event = 0;
+
+    /* This interrupt handler is called from USART irq */
+    uint8_t *buf = (uint8_t*)obj->rx_buff.buffer;
+
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        /* Determine the source of the interrupt */
+        if(LEUART_IntGetEnabled(obj->serial.periph.leuart) & LEUART_IF_PERR) {
+            /* Parity error has occurred, and we are notifying. */
+            LEUART_IntClear(obj->serial.periph.leuart, LEUART_IFC_PERR);
+            serial_rx_abort_asynch(obj);
+            return SERIAL_EVENT_RX_PARITY_ERROR;
+        }
+
+        if(LEUART_IntGetEnabled(obj->serial.periph.leuart) & LEUART_IF_FERR) {
+            /* Framing error has occurred, and we are notifying */
+            LEUART_IntClear(obj->serial.periph.leuart, LEUART_IFC_FERR);
+            serial_rx_abort_asynch(obj);
+            return SERIAL_EVENT_RX_FRAMING_ERROR;
+        }
+
+        if(LEUART_IntGetEnabled(obj->serial.periph.leuart) & LEUART_IF_RXOF) {
+            /* RX buffer overflow has occurred, and we are notifying */
+            LEUART_IntClear(obj->serial.periph.leuart, LEUART_IFC_RXOF);
+            serial_rx_abort_asynch(obj);
+            return SERIAL_EVENT_RX_OVERFLOW;
+        }
+
+        if((LEUART_IntGetEnabled(obj->serial.periph.leuart) & LEUART_IF_RXDATAV) || (LEUART_StatusGet(obj->serial.periph.leuart) & LEUART_STATUS_RXDATAV)) {
+            /* Valid data in buffer. Determine course of action: continue receiving or interrupt */
+            if(obj->rx_buff.pos >= (obj->rx_buff.length - 1)) {
+                /* Last char, transfer complete. Switch off interrupt and return event. */
+                buf[obj->rx_buff.pos] = LEUART_RxDataGet(obj->serial.periph.leuart);
+
+                event |= SERIAL_EVENT_RX_COMPLETE;
+
+                if((buf[obj->rx_buff.pos] == obj->char_match) && (obj->serial.events & SERIAL_EVENT_RX_CHARACTER_MATCH)) event |= SERIAL_EVENT_RX_CHARACTER_MATCH;
+
+                serial_rx_abort_asynch(obj);
+                return event & obj->serial.events;
+            } else {
+                /* There's still space in the receive buffer */
+                while((LEUART_StatusGet(obj->serial.periph.leuart) & LEUART_STATUS_RXDATAV) && (obj->rx_buff.pos <= (obj->rx_buff.length - 1))) {
+                    bool aborting = false;
+                    buf[obj->rx_buff.pos] = LEUART_RxDataGet(obj->serial.periph.leuart);
+                    obj->rx_buff.pos++;
+
+                    /* Check for character match event */
+                    if((buf[obj->rx_buff.pos - 1] == obj->char_match) && (obj->serial.events & SERIAL_EVENT_RX_CHARACTER_MATCH)) {
+                        aborting = true;
+                        event |= SERIAL_EVENT_RX_CHARACTER_MATCH;
+                    }
+
+                    /* Check for final char event */
+                    if(obj->rx_buff.pos >= (obj->rx_buff.length)) {
+                        aborting = true;
+                        event |= SERIAL_EVENT_RX_COMPLETE & obj->serial.events;
+                    }
+
+                    if(aborting) {
+                        serial_rx_abort_asynch(obj);
+                        return event & obj->serial.events;
+                    }
+                }
+            }
+        }
+    } else {
+        /* Determine the source of the interrupt */
+        if(USART_IntGetEnabled(obj->serial.periph.uart) & USART_IF_PERR) {
+            /* Parity error has occurred, and we are notifying. */
+            USART_IntClear(obj->serial.periph.uart, USART_IFC_PERR);
+            serial_rx_abort_asynch(obj);
+            return SERIAL_EVENT_RX_PARITY_ERROR;
+        }
+
+        if(USART_IntGetEnabled(obj->serial.periph.uart) & USART_IF_FERR) {
+            /* Framing error has occurred, and we are notifying */
+            USART_IntClear(obj->serial.periph.uart, USART_IFC_FERR);
+            serial_rx_abort_asynch(obj);
+            return SERIAL_EVENT_RX_FRAMING_ERROR;
+        }
+
+        if(USART_IntGetEnabled(obj->serial.periph.uart) & USART_IF_RXOF) {
+            /* RX buffer overflow has occurred, and we are notifying */
+            USART_IntClear(obj->serial.periph.uart, USART_IFC_RXOF);
+            serial_rx_abort_asynch(obj);
+            return SERIAL_EVENT_RX_OVERFLOW;
+        }
+
+        if((USART_IntGetEnabled(obj->serial.periph.uart) & USART_IF_RXDATAV) || (USART_StatusGet(obj->serial.periph.uart) & USART_STATUS_RXFULL)) {
+            /* Valid data in buffer. Determine course of action: continue receiving or interrupt */
+            if(obj->rx_buff.pos >= (obj->rx_buff.length - 1)) {
+                /* Last char, transfer complete. Switch off interrupt and return event. */
+                buf[obj->rx_buff.pos] = USART_RxDataGet(obj->serial.periph.uart);
+
+                event |= SERIAL_EVENT_RX_COMPLETE;
+
+                if((buf[obj->rx_buff.pos] == obj->char_match) && (obj->serial.events & SERIAL_EVENT_RX_CHARACTER_MATCH)) event |= SERIAL_EVENT_RX_CHARACTER_MATCH;
+
+                serial_rx_abort_asynch(obj);
+                return event & obj->serial.events;
+            } else {
+                /* There's still space in the receive buffer */
+                while(((USART_StatusGet(obj->serial.periph.uart) & USART_STATUS_RXDATAV) || (USART_StatusGet(obj->serial.periph.uart) & USART_IF_RXFULL)) && (obj->rx_buff.pos <= (obj->rx_buff.length - 1))) {
+                    bool aborting = false;
+                    buf[obj->rx_buff.pos] = USART_RxDataGet(obj->serial.periph.uart);
+                    obj->rx_buff.pos++;
+
+                    /* Check for character match event */
+                    if((buf[obj->rx_buff.pos - 1] == obj->char_match) && (obj->serial.events & SERIAL_EVENT_RX_CHARACTER_MATCH)) {
+                        aborting = true;
+                        event |= SERIAL_EVENT_RX_CHARACTER_MATCH;
+                    }
+
+                    /* Check for final char event */
+                    if(obj->rx_buff.pos >= (obj->rx_buff.length)) {
+                        aborting = true;
+                        event |= SERIAL_EVENT_RX_COMPLETE & obj->serial.events;
+                    }
+
+                    if(aborting) {
+                        serial_rx_abort_asynch(obj);
+                        return event & obj->serial.events;
+                    }
+                }
+            }
+        }
+    }
+
+    /* All events should have generated a return, if no return has happened, no event has been caught */
+    return 0;
+}
+
+/** Unified IRQ handler. Determines the appropriate handler to execute and returns the flags.
+ *
+ * WARNING: this code should be stateless, as re-entrancy is very possible in interrupt-based mode.
+ */
+int serial_irq_handler_asynch(serial_t *obj)
+{
+    /* First, check if we're running in DMA mode */
+    if(serial_dma_irq_fired[obj->serial.dmaOptionsRX.dmaChannel]) {
+        /* Clean up */
+        serial_dma_irq_fired[obj->serial.dmaOptionsRX.dmaChannel] = false;
+        serial_rx_abort_asynch(obj);
+
+        /* Notify CPP land of RX completion */
+        return SERIAL_EVENT_RX_COMPLETE & obj->serial.events;
+    } else if (serial_dma_irq_fired[obj->serial.dmaOptionsTX.dmaChannel]) {
+        if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+            if(obj->serial.periph.leuart->IEN & LEUART_IEN_TXC){
+                LEUART_IntDisable(obj->serial.periph.leuart,LEUART_IEN_TXC);
+                /* Clean up */
+                serial_dma_irq_fired[obj->serial.dmaOptionsTX.dmaChannel] = false;
+                serial_tx_abort_asynch(obj);
+                /* Notify CPP land of completion */
+                return SERIAL_EVENT_TX_COMPLETE & obj->serial.events;
+            }else{
+                LEUART_IntEnable(obj->serial.periph.leuart,LEUART_IEN_TXC);
+            }
+        }else{
+            if(obj->serial.periph.uart->IEN & USART_IEN_TXC){
+                USART_IntDisable(obj->serial.periph.leuart,USART_IEN_TXC);
+                /* Clean up */
+                serial_dma_irq_fired[obj->serial.dmaOptionsTX.dmaChannel] = false;
+                serial_tx_abort_asynch(obj);
+                /* Notify CPP land of completion */
+                return SERIAL_EVENT_TX_COMPLETE & obj->serial.events;
+            }else{
+                USART_IntEnable(obj->serial.periph.leuart,USART_IEN_TXC);
+            }
+        }
+    } else {
+        /* Check the NVIC to see which interrupt we're running from
+         * Also make sure to prioritize RX */
+        if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+            //Different method of checking tx vs rx for LEUART
+            if(LEUART_IntGetEnabled(obj->serial.periph.leuart) & (LEUART_IF_RXDATAV | LEUART_IF_FERR | LEUART_IF_PERR | LEUART_IF_RXOF)) {
+                return serial_rx_irq_handler_asynch(obj);
+            } else if(LEUART_StatusGet(obj->serial.periph.leuart) & (LEUART_STATUS_TXBL | LEUART_STATUS_TXC)) {
+                return serial_tx_irq_handler_asynch(obj);
+            }
+        } else {
+            if(USART_IntGetEnabled(obj->serial.periph.uart) & (USART_IF_RXDATAV | USART_IF_RXOF | USART_IF_PERR | USART_IF_FERR)) {
+                return serial_rx_irq_handler_asynch(obj);
+            } else if(USART_StatusGet(obj->serial.periph.uart) & (USART_STATUS_TXBL | USART_STATUS_TXC)){
+                return serial_tx_irq_handler_asynch(obj);
+            }
+        }
+    }
+
+    // All should be done now
+    return 0;
+}
+
+/** Abort the ongoing TX transaction. It disables the enabled interupt for TX and
+ *  flush TX hardware buffer if TX FIFO is used
+ *
+ * @param obj The serial object
+ */
+void serial_tx_abort_asynch(serial_t *obj)
+{
+    /* Stop transmitter */
+    //obj->serial.periph.uart->CMD |= USART_CMD_TXDIS;
+
+    /* Clean up */
+    switch(obj->serial.dmaOptionsTX.dmaUsageState) {
+        case DMA_USAGE_ALLOCATED:
+            /* stop DMA transfer */
+            DMA_ChannelEnable(obj->serial.dmaOptionsTX.dmaChannel, false);
+            break;
+        case DMA_USAGE_TEMPORARY_ALLOCATED:
+            /* stop DMA transfer and release channel */
+            DMA_ChannelEnable(obj->serial.dmaOptionsTX.dmaChannel, false);
+            dma_channel_free(obj->serial.dmaOptionsTX.dmaChannel);
+            obj->serial.dmaOptionsTX.dmaChannel = -1;
+            obj->serial.dmaOptionsTX.dmaUsageState = DMA_USAGE_OPPORTUNISTIC;
+            break;
+        default:
+            /* stop interrupting */
+            if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+                LEUART_IntDisable(obj->serial.periph.leuart, LEUART_IEN_TXC);
+                LEUART_IntClear(obj->serial.periph.leuart, LEUART_IFC_TXC);
+            } else {
+                USART_IntDisable(obj->serial.periph.uart, USART_IEN_TXC);
+                USART_IntClear(obj->serial.periph.uart, USART_IFC_TXC);
+            }
+            break;
+    }
+
+    /* Say that we can stop using this emode */
+#ifdef LEUART_USING_LFXO
+    if(LEUART_REF_VALID(obj->serial.periph.leuart) && (LEUART_BaudrateGet(obj->serial.periph.leuart) <= (LEUART_LF_REF_FREQ/2))){
+        unblockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE_LEUART);
+    }else{
+        unblockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE);
+    }
+#else
+    unblockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE);
+#endif
+}
+
+/** Abort the ongoing RX transaction It disables the enabled interrupt for RX and
+ *  flush RX hardware buffer if RX FIFO is used
+ *
+ * @param obj The serial object
+ */
+void serial_rx_abort_asynch(serial_t *obj)
+{
+    /* Stop receiver */
+    obj->serial.periph.uart->CMD |= USART_CMD_RXDIS;
+
+    /* Clean up */
+    switch(obj->serial.dmaOptionsRX.dmaUsageState) {
+        case DMA_USAGE_ALLOCATED:
+            /* stop DMA transfer */
+            DMA_ChannelEnable(obj->serial.dmaOptionsRX.dmaChannel, false);
+            break;
+        case DMA_USAGE_TEMPORARY_ALLOCATED:
+            /* stop DMA transfer and release channel */
+            DMA_ChannelEnable(obj->serial.dmaOptionsRX.dmaChannel, false);
+            dma_channel_free(obj->serial.dmaOptionsRX.dmaChannel);
+            obj->serial.dmaOptionsRX.dmaChannel = -1;
+            obj->serial.dmaOptionsRX.dmaUsageState = DMA_USAGE_OPPORTUNISTIC;
+            break;
+        default:
+            /* stop interrupting */
+            if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+                LEUART_IntDisable(obj->serial.periph.leuart, LEUART_IEN_RXDATAV | LEUART_IEN_PERR | LEUART_IEN_FERR | LEUART_IEN_RXOF);
+            } else {
+                USART_IntDisable(obj->serial.periph.uart, USART_IEN_RXDATAV | USART_IEN_PERR | USART_IEN_FERR | USART_IEN_RXOF);
+            }
+            break;
+    }
+
+    /*clear all set interrupts*/
+    if(LEUART_REF_VALID(obj->serial.periph.leuart)) {
+        LEUART_IntClear(obj->serial.periph.leuart, LEUART_IFC_PERR | LEUART_IFC_FERR | LEUART_IFC_RXOF);
+    }else{
+        USART_IntClear(obj->serial.periph.uart,  USART_IFC_PERR | USART_IFC_FERR | USART_IFC_RXOF);
+    }
+
+    /* Say that we can stop using this emode */
+#ifdef LEUART_USING_LFXO
+    if(LEUART_REF_VALID(obj->serial.periph.leuart) && (LEUART_BaudrateGet(obj->serial.periph.leuart) <= (LEUART_LF_REF_FREQ/2))){
+        unblockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE_LEUART);
+    }else{
+        unblockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE);
+    }
+#else
+    unblockSleepMode(SERIAL_LEAST_ACTIVE_SLEEPMODE);
+#endif
+}
+
+#endif //DEVICE_SERIAL_ASYNCH
+#endif //DEVICE_SERIAL