Diff: TARGET_LPC546XX/TOOLCHAIN_IAR/fsl_usart.h

Revision:

171:3a7713b1edbc

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TARGET_LPC546XX/TOOLCHAIN_IAR/fsl_usart.h	Thu Nov 08 11:45:42 2018 +0000
@@ -0,0 +1,667 @@
+/*
+ * The Clear BSD License
+ * Copyright (c) 2016, Freescale Semiconductor, Inc.
+ * Copyright 2016-2017 NXP
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted (subject to the limitations in the disclaimer below) provided
+ * that the following conditions are met:
+ *
+ * o Redistributions of source code must retain the above copyright notice, this list
+ *   of conditions and the following disclaimer.
+ *
+ * o Redistributions in binary form must reproduce the above copyright notice, this
+ *   list of conditions and the following disclaimer in the documentation and/or
+ *   other materials provided with the distribution.
+ *
+ * o Neither the name of the copyright holder nor the names of its
+ *   contributors may be used to endorse or promote products derived from this
+ *   software without specific prior written permission.
+ *
+ * NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED BY THIS LICENSE.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _FSL_USART_H_
+#define _FSL_USART_H_
+
+#include "fsl_common.h"
+
+/*!
+ * @addtogroup usart_driver
+ * @{
+ */
+
+/*******************************************************************************
+ * Definitions
+ ******************************************************************************/
+
+/*! @name Driver version */
+/*@{*/
+/*! @brief USART driver version 2.0.0. */
+#define FSL_USART_DRIVER_VERSION (MAKE_VERSION(2, 0, 0))
+/*@}*/
+
+#define USART_FIFOTRIG_TXLVL_GET(base) (((base)->FIFOTRIG & USART_FIFOTRIG_TXLVL_MASK) >> USART_FIFOTRIG_TXLVL_SHIFT)
+#define USART_FIFOTRIG_RXLVL_GET(base) (((base)->FIFOTRIG & USART_FIFOTRIG_RXLVL_MASK) >> USART_FIFOTRIG_RXLVL_SHIFT)
+
+/*! @brief Error codes for the USART driver. */
+enum _usart_status
+{
+    kStatus_USART_TxBusy = MAKE_STATUS(kStatusGroup_LPC_USART, 0),              /*!< Transmitter is busy. */
+    kStatus_USART_RxBusy = MAKE_STATUS(kStatusGroup_LPC_USART, 1),              /*!< Receiver is busy. */
+    kStatus_USART_TxIdle = MAKE_STATUS(kStatusGroup_LPC_USART, 2),              /*!< USART transmitter is idle. */
+    kStatus_USART_RxIdle = MAKE_STATUS(kStatusGroup_LPC_USART, 3),              /*!< USART receiver is idle. */
+    kStatus_USART_TxError = MAKE_STATUS(kStatusGroup_LPC_USART, 7),             /*!< Error happens on txFIFO. */
+    kStatus_USART_RxError = MAKE_STATUS(kStatusGroup_LPC_USART, 9),             /*!< Error happens on rxFIFO. */
+    kStatus_USART_RxRingBufferOverrun = MAKE_STATUS(kStatusGroup_LPC_USART, 8), /*!< Error happens on rx ring buffer */
+    kStatus_USART_NoiseError = MAKE_STATUS(kStatusGroup_LPC_USART, 10),         /*!< USART noise error. */
+    kStatus_USART_FramingError = MAKE_STATUS(kStatusGroup_LPC_USART, 11),       /*!< USART framing error. */
+    kStatus_USART_ParityError = MAKE_STATUS(kStatusGroup_LPC_USART, 12),        /*!< USART parity error. */
+    kStatus_USART_BaudrateNotSupport =
+        MAKE_STATUS(kStatusGroup_LPC_USART, 13), /*!< Baudrate is not support in current clock source */
+};
+
+/*! @brief USART parity mode. */
+typedef enum _usart_parity_mode
+{
+    kUSART_ParityDisabled = 0x0U, /*!< Parity disabled */
+    kUSART_ParityEven = 0x2U,     /*!< Parity enabled, type even, bit setting: PE|PT = 10 */
+    kUSART_ParityOdd = 0x3U,      /*!< Parity enabled, type odd,  bit setting: PE|PT = 11 */
+} usart_parity_mode_t;
+
+/*! @brief USART stop bit count. */
+typedef enum _usart_stop_bit_count
+{
+    kUSART_OneStopBit = 0U, /*!< One stop bit */
+    kUSART_TwoStopBit = 1U, /*!< Two stop bits */
+} usart_stop_bit_count_t;
+
+/*! @brief USART data size. */
+typedef enum _usart_data_len
+{
+    kUSART_7BitsPerChar = 0U, /*!< Seven bit mode */
+    kUSART_8BitsPerChar = 1U, /*!< Eight bit mode */
+} usart_data_len_t;
+
+/*! @brief txFIFO watermark values */
+typedef enum _usart_txfifo_watermark
+{
+    kUSART_TxFifo0 = 0, /*!< USART tx watermark is empty */
+    kUSART_TxFifo1 = 1, /*!< USART tx watermark at 1 item */
+    kUSART_TxFifo2 = 2, /*!< USART tx watermark at 2 items */
+    kUSART_TxFifo3 = 3, /*!< USART tx watermark at 3 items */
+    kUSART_TxFifo4 = 4, /*!< USART tx watermark at 4 items */
+    kUSART_TxFifo5 = 5, /*!< USART tx watermark at 5 items */
+    kUSART_TxFifo6 = 6, /*!< USART tx watermark at 6 items */
+    kUSART_TxFifo7 = 7, /*!< USART tx watermark at 7 items */
+} usart_txfifo_watermark_t;
+
+/*! @brief rxFIFO watermark values */
+typedef enum _usart_rxfifo_watermark
+{
+    kUSART_RxFifo1 = 0, /*!< USART rx watermark at 1 item */
+    kUSART_RxFifo2 = 1, /*!< USART rx watermark at 2 items */
+    kUSART_RxFifo3 = 2, /*!< USART rx watermark at 3 items */
+    kUSART_RxFifo4 = 3, /*!< USART rx watermark at 4 items */
+    kUSART_RxFifo5 = 4, /*!< USART rx watermark at 5 items */
+    kUSART_RxFifo6 = 5, /*!< USART rx watermark at 6 items */
+    kUSART_RxFifo7 = 6, /*!< USART rx watermark at 7 items */
+    kUSART_RxFifo8 = 7, /*!< USART rx watermark at 8 items */
+} usart_rxfifo_watermark_t;
+
+/*!
+ * @brief USART interrupt configuration structure, default settings all disabled.
+ */
+enum _usart_interrupt_enable
+{
+    kUSART_TxErrorInterruptEnable = (USART_FIFOINTENSET_TXERR_MASK),
+    kUSART_RxErrorInterruptEnable = (USART_FIFOINTENSET_RXERR_MASK),
+    kUSART_TxLevelInterruptEnable = (USART_FIFOINTENSET_TXLVL_MASK),
+    kUSART_RxLevelInterruptEnable = (USART_FIFOINTENSET_RXLVL_MASK),
+};
+
+/*!
+ * @brief USART status flags.
+ *
+ * This provides constants for the USART status flags for use in the USART functions.
+ */
+enum _usart_flags
+{
+    kUSART_TxError = (USART_FIFOSTAT_TXERR_MASK),                 /*!< TEERR bit, sets if TX buffer is error */
+    kUSART_RxError = (USART_FIFOSTAT_RXERR_MASK),                 /*!< RXERR bit, sets if RX buffer is error */
+    kUSART_TxFifoEmptyFlag = (USART_FIFOSTAT_TXEMPTY_MASK),       /*!< TXEMPTY bit, sets if TX buffer is empty */
+    kUSART_TxFifoNotFullFlag = (USART_FIFOSTAT_TXNOTFULL_MASK),   /*!< TXNOTFULL bit, sets if TX buffer is not full */
+    kUSART_RxFifoNotEmptyFlag = (USART_FIFOSTAT_RXNOTEMPTY_MASK), /*!< RXNOEMPTY bit, sets if RX buffer is not empty */
+    kUSART_RxFifoFullFlag = (USART_FIFOSTAT_RXFULL_MASK),         /*!< RXFULL bit, sets if RX buffer is full */
+};
+
+/*! @brief USART configuration structure. */
+typedef struct _usart_config
+{
+    uint32_t baudRate_Bps;                /*!< USART baud rate  */
+    usart_parity_mode_t parityMode;       /*!< Parity mode, disabled (default), even, odd */
+    usart_stop_bit_count_t stopBitCount;  /*!< Number of stop bits, 1 stop bit (default) or 2 stop bits  */
+    usart_data_len_t bitCountPerChar;     /*!< Data length - 7 bit, 8 bit  */
+    bool loopback;                        /*!< Enable peripheral loopback */
+    bool enableRx;                        /*!< Enable RX */
+    bool enableTx;                        /*!< Enable TX */
+    usart_txfifo_watermark_t txWatermark; /*!< txFIFO watermark */
+    usart_rxfifo_watermark_t rxWatermark; /*!< rxFIFO watermark */
+} usart_config_t;
+
+/*! @brief USART transfer structure. */
+typedef struct _usart_transfer
+{
+    uint8_t *data;   /*!< The buffer of data to be transfer.*/
+    size_t dataSize; /*!< The byte count to be transfer. */
+} usart_transfer_t;
+
+/* Forward declaration of the handle typedef. */
+typedef struct _usart_handle usart_handle_t;
+
+/*! @brief USART transfer callback function. */
+typedef void (*usart_transfer_callback_t)(USART_Type *base, usart_handle_t *handle, status_t status, void *userData);
+
+/*! @brief USART handle structure. */
+struct _usart_handle
+{
+    uint8_t *volatile txData;   /*!< Address of remaining data to send. */
+    volatile size_t txDataSize; /*!< Size of the remaining data to send. */
+    size_t txDataSizeAll;       /*!< Size of the data to send out. */
+    uint8_t *volatile rxData;   /*!< Address of remaining data to receive. */
+    volatile size_t rxDataSize; /*!< Size of the remaining data to receive. */
+    size_t rxDataSizeAll;       /*!< Size of the data to receive. */
+
+    uint8_t *rxRingBuffer;              /*!< Start address of the receiver ring buffer. */
+    size_t rxRingBufferSize;            /*!< Size of the ring buffer. */
+    volatile uint16_t rxRingBufferHead; /*!< Index for the driver to store received data into ring buffer. */
+    volatile uint16_t rxRingBufferTail; /*!< Index for the user to get data from the ring buffer. */
+
+    usart_transfer_callback_t callback; /*!< Callback function. */
+    void *userData;                     /*!< USART callback function parameter.*/
+
+    volatile uint8_t txState; /*!< TX transfer state. */
+    volatile uint8_t rxState; /*!< RX transfer state */
+
+    usart_txfifo_watermark_t txWatermark; /*!< txFIFO watermark */
+    usart_rxfifo_watermark_t rxWatermark; /*!< rxFIFO watermark */
+};
+
+/*******************************************************************************
+ * API
+ ******************************************************************************/
+
+#if defined(__cplusplus)
+extern "C" {
+#endif /* _cplusplus */
+
+/*! @brief Returns instance number for USART peripheral base address. */
+uint32_t USART_GetInstance(USART_Type *base);
+
+/*!
+ * @name Initialization and deinitialization
+ * @{
+ */
+
+/*!
+ * @brief Initializes a USART instance with user configuration structure and peripheral clock.
+ *
+ * This function configures the USART module with the user-defined settings. The user can configure the configuration
+ * structure and also get the default configuration by using the USART_GetDefaultConfig() function.
+ * Example below shows how to use this API to configure USART.
+ * @code
+ *  usart_config_t usartConfig;
+ *  usartConfig.baudRate_Bps = 115200U;
+ *  usartConfig.parityMode = kUSART_ParityDisabled;
+ *  usartConfig.stopBitCount = kUSART_OneStopBit;
+ *  USART_Init(USART1, &usartConfig, 20000000U);
+ * @endcode
+ *
+ * @param base USART peripheral base address.
+ * @param config Pointer to user-defined configuration structure.
+ * @param srcClock_Hz USART clock source frequency in HZ.
+ * @retval kStatus_USART_BaudrateNotSupport Baudrate is not support in current clock source.
+ * @retval kStatus_InvalidArgument USART base address is not valid
+ * @retval kStatus_Success Status USART initialize succeed
+ */
+status_t USART_Init(USART_Type *base, const usart_config_t *config, uint32_t srcClock_Hz);
+
+/*!
+ * @brief Deinitializes a USART instance.
+ *
+ * This function waits for TX complete, disables TX and RX, and disables the USART clock.
+ *
+ * @param base USART peripheral base address.
+ */
+void USART_Deinit(USART_Type *base);
+
+/*!
+ * @brief Gets the default configuration structure.
+ *
+ * This function initializes the USART configuration structure to a default value. The default
+ * values are:
+ *   usartConfig->baudRate_Bps = 115200U;
+ *   usartConfig->parityMode = kUSART_ParityDisabled;
+ *   usartConfig->stopBitCount = kUSART_OneStopBit;
+ *   usartConfig->bitCountPerChar = kUSART_8BitsPerChar;
+ *   usartConfig->loopback = false;
+ *   usartConfig->enableTx = false;
+ *   usartConfig->enableRx = false;
+ *
+ * @param config Pointer to configuration structure.
+ */
+void USART_GetDefaultConfig(usart_config_t *config);
+
+/*!
+ * @brief Sets the USART instance baud rate.
+ *
+ * This function configures the USART module baud rate. This function is used to update
+ * the USART module baud rate after the USART module is initialized by the USART_Init.
+ * @code
+ *  USART_SetBaudRate(USART1, 115200U, 20000000U);
+ * @endcode
+ *
+ * @param base USART peripheral base address.
+ * @param baudrate_Bps USART baudrate to be set.
+ * @param srcClock_Hz USART clock source freqency in HZ.
+ * @retval kStatus_USART_BaudrateNotSupport Baudrate is not support in current clock source.
+ * @retval kStatus_Success Set baudrate succeed.
+ * @retval kStatus_InvalidArgument One or more arguments are invalid.
+ */
+status_t USART_SetBaudRate(USART_Type *base, uint32_t baudrate_Bps, uint32_t srcClock_Hz);
+
+/* @} */
+
+/*!
+ * @name Status
+ * @{
+ */
+
+/*!
+ * @brief Get USART status flags.
+ *
+ * This function get all USART status flags, the flags are returned as the logical
+ * OR value of the enumerators @ref _usart_flags. To check a specific status,
+ * compare the return value with enumerators in @ref _usart_flags.
+ * For example, to check whether the TX is empty:
+ * @code
+ *     if (kUSART_TxFifoNotFullFlag & USART_GetStatusFlags(USART1))
+ *     {
+ *         ...
+ *     }
+ * @endcode
+ *
+ * @param base USART peripheral base address.
+ * @return USART status flags which are ORed by the enumerators in the _usart_flags.
+ */
+static inline uint32_t USART_GetStatusFlags(USART_Type *base)
+{
+    return base->FIFOSTAT;
+}
+
+/*!
+ * @brief Clear USART status flags.
+ *
+ * This function clear supported USART status flags
+ * Flags that can be cleared or set are:
+ *      kUSART_TxError
+ *      kUSART_RxError
+ * For example:
+ * @code
+ *     USART_ClearStatusFlags(USART1, kUSART_TxError | kUSART_RxError)
+ * @endcode
+ *
+ * @param base USART peripheral base address.
+ * @param mask status flags to be cleared.
+ */
+static inline void USART_ClearStatusFlags(USART_Type *base, uint32_t mask)
+{
+    /* Only TXERR, RXERR fields support write. Remaining fields should be set to zero */
+    base->FIFOSTAT = mask & (USART_FIFOSTAT_TXERR_MASK | USART_FIFOSTAT_RXERR_MASK);
+}
+
+/* @} */
+
+/*!
+ * @name Interrupts
+ * @{
+ */
+
+/*!
+ * @brief Enables USART interrupts according to the provided mask.
+ *
+ * This function enables the USART interrupts according to the provided mask. The mask
+ * is a logical OR of enumeration members. See @ref _usart_interrupt_enable.
+ * For example, to enable TX empty interrupt and RX full interrupt:
+ * @code
+ *     USART_EnableInterrupts(USART1, kUSART_TxLevelInterruptEnable | kUSART_RxLevelInterruptEnable);
+ * @endcode
+ *
+ * @param base USART peripheral base address.
+ * @param mask The interrupts to enable. Logical OR of @ref _usart_interrupt_enable.
+ */
+static inline void USART_EnableInterrupts(USART_Type *base, uint32_t mask)
+{
+    base->FIFOINTENSET = mask & 0xF;
+}
+
+/*!
+ * @brief Disables USART interrupts according to a provided mask.
+ *
+ * This function disables the USART interrupts according to a provided mask. The mask
+ * is a logical OR of enumeration members. See @ref _usart_interrupt_enable.
+ * This example shows how to disable the TX empty interrupt and RX full interrupt:
+ * @code
+ *     USART_DisableInterrupts(USART1, kUSART_TxLevelInterruptEnable | kUSART_RxLevelInterruptEnable);
+ * @endcode
+ *
+ * @param base USART peripheral base address.
+ * @param mask The interrupts to disable. Logical OR of @ref _usart_interrupt_enable.
+ */
+static inline void USART_DisableInterrupts(USART_Type *base, uint32_t mask)
+{
+    base->FIFOINTENCLR = mask & 0xF;
+}
+
+/*!
+ * @brief Returns enabled USART interrupts.
+ *
+ * This function returns the enabled USART interrupts.
+ *
+ * @param base USART peripheral base address.
+ */
+static inline uint32_t USART_GetEnabledInterrupts(USART_Type *base)
+{
+    return base->FIFOINTENSET;
+}
+
+/*!
+* @brief Enable DMA for Tx
+*/
+static inline void USART_EnableTxDMA(USART_Type *base, bool enable)
+{
+    if (enable)
+    {
+        base->FIFOCFG |= USART_FIFOCFG_DMATX_MASK;
+    }
+    else
+    {
+        base->FIFOCFG &= ~(USART_FIFOCFG_DMATX_MASK);
+    }
+}
+
+/*!
+* @brief Enable DMA for Rx
+*/
+static inline void USART_EnableRxDMA(USART_Type *base, bool enable)
+{
+    if (enable)
+    {
+        base->FIFOCFG |= USART_FIFOCFG_DMARX_MASK;
+    }
+    else
+    {
+        base->FIFOCFG &= ~(USART_FIFOCFG_DMARX_MASK);
+    }
+}
+
+/* @} */
+
+/*!
+ * @name Bus Operations
+ * @{
+ */
+
+/*!
+ * @brief Writes to the FIFOWR register.
+ *
+ * This function writes data to the txFIFO directly. The upper layer must ensure
+ * that txFIFO has space for data to write before calling this function.
+ *
+ * @param base USART peripheral base address.
+ * @param data The byte to write.
+ */
+static inline void USART_WriteByte(USART_Type *base, uint8_t data)
+{
+    base->FIFOWR = data;
+}
+
+/*!
+ * @brief Reads the FIFORD register directly.
+ *
+ * This function reads data from the rxFIFO directly. The upper layer must
+ * ensure that the rxFIFO is not empty before calling this function.
+ *
+ * @param base USART peripheral base address.
+ * @return The byte read from USART data register.
+ */
+static inline uint8_t USART_ReadByte(USART_Type *base)
+{
+    return base->FIFORD;
+}
+
+/*!
+ * @brief Writes to the TX register using a blocking method.
+ *
+ * This function polls the TX register, waits for the TX register to be empty or for the TX FIFO
+ * to have room and writes data to the TX buffer.
+ *
+ * @param base USART peripheral base address.
+ * @param data Start address of the data to write.
+ * @param length Size of the data to write.
+ */
+void USART_WriteBlocking(USART_Type *base, const uint8_t *data, size_t length);
+
+/*!
+ * @brief Read RX data register using a blocking method.
+ *
+ * This function polls the RX register, waits for the RX register to be full or for RX FIFO to
+ * have data and read data from the TX register.
+ *
+ * @param base USART peripheral base address.
+ * @param data Start address of the buffer to store the received data.
+ * @param length Size of the buffer.
+ * @retval kStatus_USART_FramingError Receiver overrun happened while receiving data.
+ * @retval kStatus_USART_ParityError Noise error happened while receiving data.
+ * @retval kStatus_USART_NoiseError Framing error happened while receiving data.
+ * @retval kStatus_USART_RxError Overflow or underflow rxFIFO happened.
+ * @retval kStatus_Success Successfully received all data.
+ */
+status_t USART_ReadBlocking(USART_Type *base, uint8_t *data, size_t length);
+
+/* @} */
+
+/*!
+ * @name Transactional
+ * @{
+ */
+
+/*!
+ * @brief Initializes the USART handle.
+ *
+ * This function initializes the USART handle which can be used for other USART
+ * transactional APIs. Usually, for a specified USART instance,
+ * call this API once to get the initialized handle.
+ *
+ * @param base USART peripheral base address.
+ * @param handle USART handle pointer.
+ * @param callback The callback function.
+ * @param userData The parameter of the callback function.
+ */
+status_t USART_TransferCreateHandle(USART_Type *base,
+                                    usart_handle_t *handle,
+                                    usart_transfer_callback_t callback,
+                                    void *userData);
+
+/*!
+ * @brief Transmits a buffer of data using the interrupt method.
+ *
+ * This function sends data using an interrupt method. This is a non-blocking function, which
+ * returns directly without waiting for all data to be written to the TX register. When
+ * all data is written to the TX register in the IRQ handler, the USART driver calls the callback
+ * function and passes the @ref kStatus_USART_TxIdle as status parameter.
+ *
+ * @note The kStatus_USART_TxIdle is passed to the upper layer when all data is written
+ * to the TX register. However it does not ensure that all data are sent out. Before disabling the TX,
+ * check the kUSART_TransmissionCompleteFlag to ensure that the TX is finished.
+ *
+ * @param base USART peripheral base address.
+ * @param handle USART handle pointer.
+ * @param xfer USART transfer structure. See  #usart_transfer_t.
+ * @retval kStatus_Success Successfully start the data transmission.
+ * @retval kStatus_USART_TxBusy Previous transmission still not finished, data not all written to TX register yet.
+ * @retval kStatus_InvalidArgument Invalid argument.
+ */
+status_t USART_TransferSendNonBlocking(USART_Type *base, usart_handle_t *handle, usart_transfer_t *xfer);
+
+/*!
+ * @brief Sets up the RX ring buffer.
+ *
+ * This function sets up the RX ring buffer to a specific USART handle.
+ *
+ * When the RX ring buffer is used, data received are stored into the ring buffer even when the
+ * user doesn't call the USART_TransferReceiveNonBlocking() API. If there is already data received
+ * in the ring buffer, the user can get the received data from the ring buffer directly.
+ *
+ * @note When using the RX ring buffer, one byte is reserved for internal use. In other
+ * words, if @p ringBufferSize is 32, then only 31 bytes are used for saving data.
+ *
+ * @param base USART peripheral base address.
+ * @param handle USART handle pointer.
+ * @param ringBuffer Start address of the ring buffer for background receiving. Pass NULL to disable the ring buffer.
+ * @param ringBufferSize size of the ring buffer.
+ */
+void USART_TransferStartRingBuffer(USART_Type *base,
+                                   usart_handle_t *handle,
+                                   uint8_t *ringBuffer,
+                                   size_t ringBufferSize);
+
+/*!
+ * @brief Aborts the background transfer and uninstalls the ring buffer.
+ *
+ * This function aborts the background transfer and uninstalls the ring buffer.
+ *
+ * @param base USART peripheral base address.
+ * @param handle USART handle pointer.
+ */
+void USART_TransferStopRingBuffer(USART_Type *base, usart_handle_t *handle);
+
+/*!
+ * @brief Get the length of received data in RX ring buffer.
+ *
+ * @param handle USART handle pointer.
+ * @return Length of received data in RX ring buffer.
+ */
+size_t USART_TransferGetRxRingBufferLength(usart_handle_t *handle);
+
+/*!
+ * @brief Aborts the interrupt-driven data transmit.
+ *
+ * This function aborts the interrupt driven data sending. The user can get the remainBtyes to find out
+ * how many bytes are still not sent out.
+ *
+ * @param base USART peripheral base address.
+ * @param handle USART handle pointer.
+ */
+void USART_TransferAbortSend(USART_Type *base, usart_handle_t *handle);
+
+/*!
+ * @brief Get the number of bytes that have been written to USART TX register.
+ *
+ * This function gets the number of bytes that have been written to USART TX
+ * register by interrupt method.
+ *
+ * @param base USART peripheral base address.
+ * @param handle USART handle pointer.
+ * @param count Send bytes count.
+ * @retval kStatus_NoTransferInProgress No send in progress.
+ * @retval kStatus_InvalidArgument Parameter is invalid.
+ * @retval kStatus_Success Get successfully through the parameter \p count;
+ */
+status_t USART_TransferGetSendCount(USART_Type *base, usart_handle_t *handle, uint32_t *count);
+
+/*!
+ * @brief Receives a buffer of data using an interrupt method.
+ *
+ * This function receives data using an interrupt method. This is a non-blocking function, which
+ *  returns without waiting for all data to be received.
+ * If the RX ring buffer is used and not empty, the data in the ring buffer is copied and
+ * the parameter @p receivedBytes shows how many bytes are copied from the ring buffer.
+ * After copying, if the data in the ring buffer is not enough to read, the receive
+ * request is saved by the USART driver. When the new data arrives, the receive request
+ * is serviced first. When all data is received, the USART driver notifies the upper layer
+ * through a callback function and passes the status parameter @ref kStatus_USART_RxIdle.
+ * For example, the upper layer needs 10 bytes but there are only 5 bytes in the ring buffer.
+ * The 5 bytes are copied to the xfer->data and this function returns with the
+ * parameter @p receivedBytes set to 5. For the left 5 bytes, newly arrived data is
+ * saved from the xfer->data[5]. When 5 bytes are received, the USART driver notifies the upper layer.
+ * If the RX ring buffer is not enabled, this function enables the RX and RX interrupt
+ * to receive data to the xfer->data. When all data is received, the upper layer is notified.
+ *
+ * @param base USART peripheral base address.
+ * @param handle USART handle pointer.
+ * @param xfer USART transfer structure, see #usart_transfer_t.
+ * @param receivedBytes Bytes received from the ring buffer directly.
+ * @retval kStatus_Success Successfully queue the transfer into transmit queue.
+ * @retval kStatus_USART_RxBusy Previous receive request is not finished.
+ * @retval kStatus_InvalidArgument Invalid argument.
+ */
+status_t USART_TransferReceiveNonBlocking(USART_Type *base,
+                                          usart_handle_t *handle,
+                                          usart_transfer_t *xfer,
+                                          size_t *receivedBytes);
+
+/*!
+ * @brief Aborts the interrupt-driven data receiving.
+ *
+ * This function aborts the interrupt-driven data receiving. The user can get the remainBytes to find out
+ * how many bytes not received yet.
+ *
+ * @param base USART peripheral base address.
+ * @param handle USART handle pointer.
+ */
+void USART_TransferAbortReceive(USART_Type *base, usart_handle_t *handle);
+
+/*!
+ * @brief Get the number of bytes that have been received.
+ *
+ * This function gets the number of bytes that have been received.
+ *
+ * @param base USART peripheral base address.
+ * @param handle USART handle pointer.
+ * @param count Receive bytes count.
+ * @retval kStatus_NoTransferInProgress No receive in progress.
+ * @retval kStatus_InvalidArgument Parameter is invalid.
+ * @retval kStatus_Success Get successfully through the parameter \p count;
+ */
+status_t USART_TransferGetReceiveCount(USART_Type *base, usart_handle_t *handle, uint32_t *count);
+
+/*!
+ * @brief USART IRQ handle function.
+ *
+ * This function handles the USART transmit and receive IRQ request.
+ *
+ * @param base USART peripheral base address.
+ * @param handle USART handle pointer.
+ */
+void USART_TransferHandleIRQ(USART_Type *base, usart_handle_t *handle);
+
+/* @} */
+
+#if defined(__cplusplus)
+}
+#endif
+
+/*! @}*/
+
+#endif /* _FSL_USART_H_ */