Kinetis SDK v.2.0 API Reference Manual  Rev. 0
Freescale Semiconductor, Inc.
 All Data Structures Functions Variables Typedefs Enumerations Enumerator Groups Pages

Overview

The KSDK provides a peripheral driver for the Universal Asynchronous Receiver/Transmitter (UART) module of Kinetis devices.

The UART driver includes two parts: functional APIs and transactional APIs.

Functional APIs are used for UART initialization/configuration/operation for optimization/customization purpose. Using the functional API requires the knowledge of the UART peripheral and know how to organize functional APIs to meet the application requirements. All functional API use the peripheral base address as the first parameter. UART functional operation groups provide the functional APIs set.

Transactional APIs can be used to enable the peripheral quickly and in the application if the code size and performance of transactional APIs can satisfy the requirements. If the code size and performance are critical requirements, see the transactional API implementation and write custom code. All transactional APIs use the uart_handle_t as the first parameter. Initialize the handle by calling the UART_CreateHandle() API.

Transactional APIs support asynchronous transfer, which means that the functions UART_SendNonBlocking() and UART_ReceiveNonBlocking() set up an interrupt for data transfer. When the transfer completes, the upper layer is notified through a callback function with the kStatus_UART_TxIdle and kStatus_UART_RxIdle.

Transactional receive APIs support the ring buffer. Prepare the memory for the ring buffer and pass in the start address and size while calling the UART_CreateHandle(). If passing NULL, the ring buffer feature is disabled. When the ring buffer is enabled, the received data is saved to the ring buffer in the background. The UART_ReceiveNonBlocking() function first gets data from the ring buffer. If the ring buffer does not have enough data, the function first returns the data in the ring buffer and then saves the received data to user memory. When all data is received, the upper layer is informed through a callback with the kStatus_UART_RxIdle.

If the receive ring buffer is full, the upper layer is informed through a callback with the kStatus_UART_RxRingBufferOverrun. In the callback function, the upper layer reads data out from the ring buffer. If not, the oldest data is overwritten by the new data.

The ring buffer size is specified when creating the handle. Note that one byte is reserved for the ring buffer maintenance. When creating handle using the following code:

UART_CreateHandle(&handle, UART0, &ringBuffer, 32);

In this example, the buffer size is 32, but only 31 bytes are used for saving data.

Typical use case

UART Send/receive using a polling method

uint8_t ch;
UART_GetDefaultConfig(&user_config);
user_config.baudRate_Bps = 115200U;
user_config.enableTx = true;
user_config.enableRx = true;
UART_Init(UART1,&user_config,120000000U);
while(1)
{
UART_TransferReceiveBlocking(UART1, &ch, 1);
UART_TransferSendBlocking(UART1, &ch, 1);
}

UART Send/receive using an interrupt method

uart_handle_t g_uartHandle;
uart_config_t user_config;
uart_transfer_t sendXfer;
uart_transfer_t receiveXfer;
volatile bool txFinished;
volatile bool rxFinished;
uint8_t sendData[] = ['H', 'e', 'l', 'l', 'o'];
uint8_t receiveData[32];
void UART_UserCallback(uart_handle_t *handle, status_t status, void *userData)
{
userData = userData;
if (kStatus_UART_TxIdle == status)
{
txFinished = true;
}
if (kStatus_UART_RxIdle == status)
{
rxFinished = true;
}
}
void main(void)
{
//...
UART_GetDefaultConfig(&user_config);
user_config.baudRate_Bps = 115200U;
user_config.enableTx = true;
user_config.enableRx = true;
UART_Init(UART1, &user_config, 120000000U);
UART_CreateHandle(&g_uartHandle, UART1, NULL, 0);
UART_SetTransferCallback(&g_uartHandle, UART_UserCallback, NULL);
// Prepare to send.
sendXfer.data = sendData
sendXfer.dataSize = sizeof(sendData)/sizeof(sendData[0]);
txFinished = false;
// Send out.
UART_SendNonBlocking(&g_uartHandle, &sendXfer);
// Wait send finished.
while (!txFinished)
{
}
// Prepare to receive.
receiveXfer.data = receiveData;
receiveXfer.dataSize = sizeof(receiveData)/sizeof(receiveData[0]);
rxFinished = false;
// Receive.
UART_ReceiveNonBlocking(&g_uartHandle, &receiveXfer, NULL);
// Wait receive finished.
while (!rxFinished)
{
}
// ...
}

UART Receive using the ringbuffer feature

#define RING_BUFFER_SIZE 64
#define RX_DATA_SIZE 32
uart_handle_t g_uartHandle;
uart_config_t user_config;
uart_transfer_t sendXfer;
uart_transfer_t receiveXfer;
volatile bool txFinished;
volatile bool rxFinished;
uint8_t receiveData[RX_DATA_SIZE];
uint8_t ringBuffer[RING_BUFFER_SIZE];
void UART_UserCallback(uart_handle_t *handle, status_t status, void *userData)
{
userData = userData;
if (kStatus_UART_RxIdle == status)
{
rxFinished = true;
}
}
void main(void)
{
size_t bytesRead;
//...
UART_GetDefaultConfig(&user_config);
user_config.baudRate_Bps = 115200U;
user_config.enableTx = true;
user_config.enableRx = true;
UART_Init(UART1, &user_config, 120000000U);
UART_CreateHandle(&g_uartHandle, UART1, &ringBuffer, RING_BUFFER_SIZE);
UART_SetTransferCallback(&g_uartHandle, UART_UserCallback, NULL);
// Now the RX is working in background, receive in to ring buffer.
// Prepare to receive.
receiveXfer.data = receiveData;
receiveXfer.dataSize = RX_DATA_SIZE;
rxFinished = false;
// Receive.
UART_ReceiveNonBlocking(&g_uartHandle, &receiveXfer, &bytesRead);
if (bytesRead = RX_DATA_SIZE) /* Have read enough data.
{
;
}
else
{
if (bytesRead) /* Received some data, process first.
{
;
}
// Wait receive finished.
while (!rxFinished)
{
}
}
// ...
}

UART Send/Receive using the DMA method

uart_handle_t g_uartHandle;
dma_handle_t g_uartTxDmaHandle;
dma_handle_t g_uartRxDmaHandle;
uart_config_t user_config;
uart_transfer_t sendXfer;
uart_transfer_t receiveXfer;
volatile bool txFinished;
volatile bool rxFinished;
uint8_t sendData[] = ['H', 'e', 'l', 'l', 'o'];
uint8_t receiveData[32];
void UART_UserCallback(uart_handle_t *handle, status_t status, void *userData)
{
userData = userData;
if (kStatus_UART_TxIdle == status)
{
txFinished = true;
}
if (kStatus_UART_RxIdle == status)
{
rxFinished = true;
}
}
void main(void)
{
//...
UART_GetDefaultConfig(&user_config);
user_config.baudRate_Bps = 115200U;
user_config.enableTx = true;
user_config.enableRx = true;
UART_Init(UART1, &user_config, 120000000U);
// Set up the DMA
DMAMUX_Init(DMAMUX0);
DMAMUX_SetSource(DMAMUX0, UART_TX_DMA_CHANNEL, UART_TX_DMA_REQUEST);
DMAMUX_EnableChannel(DMAMUX0, UART_TX_DMA_CHANNEL);
DMAMUX_SetSource(DMAMUX0, UART_RX_DMA_CHANNEL, UART_RX_DMA_REQUEST);
DMAMUX_EnableChannel(DMAMUX0, UART_RX_DMA_CHANNEL);
DMA_Init(DMA0);
/* Create DMA handle.
DMA_CreateHandle(&g_uartTxDmaHandle, DMA0, UART_TX_DMA_CHANNEL);
DMA_CreateHandle(&g_uartRxDmaHandle, DMA0, UART_RX_DMA_CHANNEL);
UART_CreateHandleDMA(&g_uartHandle, UART1, &g_uartTxDmaHandle, &g_uartRxDmaHandle);
UART_SetTransferCallbackDMA(&g_uartDmaHandle, UART_UserCallback, NULL);
// Prepare to send.
sendXfer.data = sendData
sendXfer.dataSize = sizeof(sendData)/sizeof(sendData[0]);
txFinished = false;
// Send out.
UART_SendDMA(&g_uartHandle, &sendXfer);
// Wait send finished.
while (!txFinished)
{
}
// Prepare to receive.
receiveXfer.data = receiveData;
receiveXfer.dataSize = sizeof(receiveData)/sizeof(receiveData[0]);
rxFinished = false;
// Receive.
UART_ReceiveDMA(&g_uartHandle, &receiveXfer, NULL);
// Wait receive finished.
while (!rxFinished)
{
}
// ...
}

Modules

 UART DMA Driver
 
 UART eDMA Driver
 

Files

file  fsl_uart.h
 

Data Structures

struct  uart_config_t
 UART configuration structure. More...
 
struct  uart_transfer_t
 UART transfer structure. More...
 
struct  uart_handle_t
 UART handle structure. More...
 

Typedefs

typedef void(* uart_transfer_callback_t )(UART_Type *base, uart_handle_t *handle, status_t status, void *userData)
 UART transfer callback function. More...
 

Enumerations

enum  _uart_status {
  kStatus_UART_TxBusy = MAKE_STATUS(kStatusGroup_UART, 0),
  kStatus_UART_RxBusy = MAKE_STATUS(kStatusGroup_UART, 1),
  kStatus_UART_TxIdle = MAKE_STATUS(kStatusGroup_UART, 2),
  kStatus_UART_RxIdle = MAKE_STATUS(kStatusGroup_UART, 3),
  kStatus_UART_TxWatermarkTooLarge = MAKE_STATUS(kStatusGroup_UART, 4),
  kStatus_UART_RxWatermarkTooLarge = MAKE_STATUS(kStatusGroup_UART, 5),
  kStatus_UART_FlagCannotClearManually,
  kStatus_UART_Error = MAKE_STATUS(kStatusGroup_UART, 7),
  kStatus_UART_RxRingBufferOverrun = MAKE_STATUS(kStatusGroup_UART, 8),
  kStatus_UART_RxHardwareOverrun = MAKE_STATUS(kStatusGroup_UART, 9),
  kStatus_UART_NoiseError = MAKE_STATUS(kStatusGroup_UART, 10),
  kStatus_UART_FramingError = MAKE_STATUS(kStatusGroup_UART, 11),
  kStatus_UART_ParityError = MAKE_STATUS(kStatusGroup_UART, 12)
}
 Error codes for the UART driver. More...
 
enum  uart_parity_mode_t {
  kUART_ParityDisabled = 0x0U,
  kUART_ParityEven = 0x2U,
  kUART_ParityOdd = 0x3U
}
 UART parity mode. More...
 
enum  uart_stop_bit_count_t {
  kUART_OneStopBit = 0U,
  kUART_TwoStopBit = 1U
}
 UART stop bit count. More...
 
enum  _uart_interrupt_enable {
  kUART_RxActiveEdgeInterruptEnable = (UART_BDH_RXEDGIE_MASK),
  kUART_TxDataRegEmptyInterruptEnable = (UART_C2_TIE_MASK << 8),
  kUART_TransmissionCompleteInterruptEnable = (UART_C2_TCIE_MASK << 8),
  kUART_RxDataRegFullInterruptEnable = (UART_C2_RIE_MASK << 8),
  kUART_IdleLineInterruptEnable = (UART_C2_ILIE_MASK << 8),
  kUART_RxOverrunInterruptEnable = (UART_C3_ORIE_MASK << 16),
  kUART_NoiseErrorInterruptEnable = (UART_C3_NEIE_MASK << 16),
  kUART_FramingErrorInterruptEnable = (UART_C3_FEIE_MASK << 16),
  kUART_ParityErrorInterruptEnable = (UART_C3_PEIE_MASK << 16)
}
 UART interrupt configuration structure, default settings all disabled. More...
 
enum  _uart_flags {
  kUART_TxDataRegEmptyFlag = (UART_S1_TDRE_MASK),
  kUART_TransmissionCompleteFlag = (UART_S1_TC_MASK),
  kUART_RxDataRegFullFlag = (UART_S1_RDRF_MASK),
  kUART_IdleLineFlag = (UART_S1_IDLE_MASK),
  kUART_RxOverrunFlag = (UART_S1_OR_MASK),
  kUART_NoiseErrorFlag = (UART_S1_NF_MASK),
  kUART_FramingErrorFlag = (UART_S1_FE_MASK),
  kUART_ParityErrorFlag = (UART_S1_PF_MASK),
  kUART_RxActiveEdgeFlag = (UART_S2_RXEDGIF_MASK << 8),
  kUART_RxActiveFlag = (UART_S2_RAF_MASK << 8)
}
 UART status flags. More...
 

Driver version

#define FSL_UART_DRIVER_VERSION   (MAKE_VERSION(2, 1, 0))
 UART driver version 2.1.0. More...
 

Initialization and deinitialization

void UART_Init (UART_Type *base, const uart_config_t *config, uint32_t srcClock_Hz)
 Initializes a UART instance with user configuration structure and peripheral clock. More...
 
void UART_Deinit (UART_Type *base)
 Deinitializes a UART instance. More...
 
void UART_GetDefaultConfig (uart_config_t *config)
 Gets the default configuration structure. More...
 
void UART_SetBaudRate (UART_Type *base, uint32_t baudRate_Bps, uint32_t srcClock_Hz)
 Sets the UART instance baud rate. More...
 

Status

uint32_t UART_GetStatusFlags (UART_Type *base)
 Get UART status flags. More...
 
status_t UART_ClearStatusFlags (UART_Type *base, uint32_t mask)
 Clears status flags with the provided mask. More...
 

Interrupts

void UART_EnableInterrupts (UART_Type *base, uint32_t mask)
 Enables UART interrupts according to the provided mask. More...
 
void UART_DisableInterrupts (UART_Type *base, uint32_t mask)
 Disables the UART interrupts according to the provided mask. More...
 
uint32_t UART_GetEnabledInterrupts (UART_Type *base)
 Gets the enabled UART interrupts. More...
 

Bus Operations

static void UART_EnableTx (UART_Type *base, bool enable)
 Enables or disables the UART transmitter. More...
 
static void UART_EnableRx (UART_Type *base, bool enable)
 Enables or disables the UART receiver. More...
 
static void UART_WriteByte (UART_Type *base, uint8_t data)
 Writes to the TX register. More...
 
static uint8_t UART_ReadByte (UART_Type *base)
 Reads the RX register directly. More...
 
void UART_WriteBlocking (UART_Type *base, const uint8_t *data, size_t length)
 Writes to the TX register using a blocking method. More...
 
status_t UART_ReadBlocking (UART_Type *base, uint8_t *data, size_t length)
 Read RX data register using a blocking method. More...
 

Transactional

void UART_TransferCreateHandle (UART_Type *base, uart_handle_t *handle, uart_transfer_callback_t callback, void *userData)
 Initializes the UART handle. More...
 
void UART_TransferStartRingBuffer (UART_Type *base, uart_handle_t *handle, uint8_t *ringBuffer, size_t ringBufferSize)
 Sets up the RX ring buffer. More...
 
void UART_TransferStopRingBuffer (UART_Type *base, uart_handle_t *handle)
 Aborts the background transfer and uninstalls the ring buffer. More...
 
status_t UART_TransferSendNonBlocking (UART_Type *base, uart_handle_t *handle, uart_transfer_t *xfer)
 Transmits a buffer of data using the interrupt method. More...
 
void UART_TransferAbortSend (UART_Type *base, uart_handle_t *handle)
 Aborts the interrupt driven data transmit. More...
 
status_t UART_TransferGetSendCount (UART_Type *base, uart_handle_t *handle, uint32_t *count)
 Get the number of bytes that have been written to UART TX register. More...
 
status_t UART_TransferReceiveNonBlocking (UART_Type *base, uart_handle_t *handle, uart_transfer_t *xfer, size_t *receivedBytes)
 Receives a buffer of data using an interrupt method. More...
 
void UART_TransferAbortReceive (UART_Type *base, uart_handle_t *handle)
 Aborts the interrupt-driven data receiving. More...
 
status_t UART_TransferGetReceiveCount (UART_Type *base, uart_handle_t *handle, uint32_t *count)
 Get the number of bytes that have been received. More...
 
void UART_TransferHandleIRQ (UART_Type *base, uart_handle_t *handle)
 UART IRQ handle function. More...
 
void UART_TransferHandleErrorIRQ (UART_Type *base, uart_handle_t *handle)
 UART Error IRQ handle function. More...
 

Data Structure Documentation

struct uart_config_t

Data Fields

uint32_t baudRate_Bps
 UART baud rate.
 
uart_parity_mode_t parityMode
 Parity mode, disabled (default), even, odd.
 
bool enableTx
 Enable TX.
 
bool enableRx
 Enable RX.
 
struct uart_transfer_t

Data Fields

uint8_t * data
 The buffer of data to be transfer. More...
 
size_t dataSize
 The byte count to be transfer. More...
 

Field Documentation

uint8_t* uart_transfer_t::data
size_t uart_transfer_t::dataSize
struct _uart_handle

Data Fields

uint8_t *volatile txData
 Address of remaining data to send. More...
 
volatile size_t txDataSize
 Size of the remaining data to send. More...
 
size_t txDataSizeAll
 Size of the data to send out. More...
 
uint8_t *volatile rxData
 Address of remaining data to receive. More...
 
volatile size_t rxDataSize
 Size of the remaining data to receive. More...
 
size_t rxDataSizeAll
 Size of the data to receive. More...
 
uint8_t * rxRingBuffer
 Start address of the receiver ring buffer. More...
 
size_t rxRingBufferSize
 Size of the ring buffer. More...
 
volatile uint16_t rxRingBufferHead
 Index for the driver to store received data into ring buffer. More...
 
volatile uint16_t rxRingBufferTail
 Index for the user to get data from the ring buffer. More...
 
uart_transfer_callback_t callback
 Callback function. More...
 
void * userData
 UART callback function parameter. More...
 
volatile uint8_t txState
 TX transfer state. More...
 
volatile uint8_t rxState
 RX transfer state.
 

Field Documentation

uint8_t* volatile uart_handle_t::txData
volatile size_t uart_handle_t::txDataSize
size_t uart_handle_t::txDataSizeAll
uint8_t* volatile uart_handle_t::rxData
volatile size_t uart_handle_t::rxDataSize
size_t uart_handle_t::rxDataSizeAll
uint8_t* uart_handle_t::rxRingBuffer
size_t uart_handle_t::rxRingBufferSize
volatile uint16_t uart_handle_t::rxRingBufferHead
volatile uint16_t uart_handle_t::rxRingBufferTail
uart_transfer_callback_t uart_handle_t::callback
void* uart_handle_t::userData
volatile uint8_t uart_handle_t::txState

Macro Definition Documentation

#define FSL_UART_DRIVER_VERSION   (MAKE_VERSION(2, 1, 0))

Typedef Documentation

typedef void(* uart_transfer_callback_t)(UART_Type *base, uart_handle_t *handle, status_t status, void *userData)

Enumeration Type Documentation

Enumerator
kStatus_UART_TxBusy 

Transmitter is busy.

kStatus_UART_RxBusy 

Receiver is busy.

kStatus_UART_TxIdle 

UART transmitter is idle.

kStatus_UART_RxIdle 

UART receiver is idle.

kStatus_UART_TxWatermarkTooLarge 

TX FIFO watermark too large.

kStatus_UART_RxWatermarkTooLarge 

RX FIFO watermark too large.

kStatus_UART_FlagCannotClearManually 

UART flag can't be manually cleared.

kStatus_UART_Error 

Error happens on UART.

kStatus_UART_RxRingBufferOverrun 

UART RX software ring buffer overrun.

kStatus_UART_RxHardwareOverrun 

UART RX receiver overrun.

kStatus_UART_NoiseError 

UART noise error.

kStatus_UART_FramingError 

UART framing error.

kStatus_UART_ParityError 

UART parity error.

Enumerator
kUART_ParityDisabled 

Parity disabled.

kUART_ParityEven 

Parity enabled, type even, bit setting: PE|PT = 10.

kUART_ParityOdd 

Parity enabled, type odd, bit setting: PE|PT = 11.

Enumerator
kUART_OneStopBit 

One stop bit.

kUART_TwoStopBit 

Two stop bits.

This structure contains the settings for all of the UART interrupt configurations.

Enumerator
kUART_RxActiveEdgeInterruptEnable 

RX active edge interrupt.

kUART_TxDataRegEmptyInterruptEnable 

Transmit data register empty interrupt.

kUART_TransmissionCompleteInterruptEnable 

Transmission complete interrupt.

kUART_RxDataRegFullInterruptEnable 

Receiver data register full interrupt.

kUART_IdleLineInterruptEnable 

Idle line interrupt.

kUART_RxOverrunInterruptEnable 

Receiver overrun interrupt.

kUART_NoiseErrorInterruptEnable 

Noise error flag interrupt.

kUART_FramingErrorInterruptEnable 

Framing error flag interrupt.

kUART_ParityErrorInterruptEnable 

Parity error flag interrupt.

This provides constants for the UART status flags for use in the UART functions.

Enumerator
kUART_TxDataRegEmptyFlag 

TX data register empty flag.

kUART_TransmissionCompleteFlag 

Transmission complete flag.

kUART_RxDataRegFullFlag 

RX data register full flag.

kUART_IdleLineFlag 

Idle line detect flag.

kUART_RxOverrunFlag 

RX overrun flag.

kUART_NoiseErrorFlag 

RX takes 3 samples of each received bit.

If any of these samples differ, noise flag sets

kUART_FramingErrorFlag 

Frame error flag, sets if logic 0 was detected where stop bit expected.

kUART_ParityErrorFlag 

If parity enabled, sets upon parity error detection.

kUART_RxActiveEdgeFlag 

RX pin active edge interrupt flag, sets when active edge detected.

kUART_RxActiveFlag 

Receiver Active Flag (RAF), sets at beginning of valid start bit.

Function Documentation

void UART_Init ( UART_Type *  base,
const uart_config_t config,
uint32_t  srcClock_Hz 
)

This function configures the UART module with the user-defined settings. The user can configure the configuration structure and also get the default configuration by using the UART_GetDefaultConfig() function. Example below shows how to use this API to configure UART.

uart_config_t uartConfig;
uartConfig.baudRate_Bps = 115200U;
uartConfig.stopBitCount = kUART_OneStopBit;
uartConfig.txFifoWatermark = 0;
uartConfig.rxFifoWatermark = 1;
UART_Init(UART1, &uartConfig, 20000000U);
Parameters
baseUART peripheral base address.
configPointer to user-defined configuration structure.
srcClock_HzUART clock source frequency in HZ.
void UART_Deinit ( UART_Type *  base)

This function waits for TX complete, disables TX and RX, and disables the UART clock.

Parameters
baseUART peripheral base address.
void UART_GetDefaultConfig ( uart_config_t config)

This function initializes the UART configuration structure to a default value. The default values are: uartConfig->baudRate_Bps = 115200U; uartConfig->bitCountPerChar = kUART_8BitsPerChar; uartConfig->parityMode = kUART_ParityDisabled; uartConfig->stopBitCount = kUART_OneStopBit; uartConfig->txFifoWatermark = 0; uartConfig->rxFifoWatermark = 1; uartConfig->enableTx = false; uartConfig->enableRx = false;

Parameters
configPointer to configuration structure.
void UART_SetBaudRate ( UART_Type *  base,
uint32_t  baudRate_Bps,
uint32_t  srcClock_Hz 
)

This function configures the UART module baud rate. This function is used to update the UART module baud rate after the UART module is initialized by the UART_Init.

UART_SetBaudRate(UART1, 115200U, 20000000U);
Parameters
baseUART peripheral base address.
baudRate_BpsUART baudrate to be set.
srcClock_HzUART clock source freqency in HZ.
uint32_t UART_GetStatusFlags ( UART_Type *  base)

This function get all UART status flags, the flags are returned as the logical OR value of the enumerators _uart_flags. To check specific status, compare the return value with enumerators in _uart_flags. For example, to check whether the TX is empty:

Parameters
baseUART peripheral base address.
Returns
UART status flags which are ORed by the enumerators in the _uart_flags.
status_t UART_ClearStatusFlags ( UART_Type *  base,
uint32_t  mask 
)

This function clears UART status flags with a provided mask. Automatically cleared flag can't be cleared by this function. Some flags can only be cleared or set by hardware itself. These flags are: kUART_TxDataRegEmptyFlag, kUART_TransmissionCompleteFlag, kUART_RxDataRegFullFlag, kUART_RxActiveFlag, kUART_NoiseErrorInRxDataRegFlag, kUART_ParityErrorInRxDataRegFlag, kUART_TxFifoEmptyFlag,kUART_RxFifoEmptyFlag Note: This API should be called when the Tx/Rx is idle, otherwise it takes no effects.

Parameters
baseUART peripheral base address.
maskThe status flags to be cleared, it is logical OR value of _uart_flags.
Return values
kStatus_UART_FlagCannotClearManuallyThe flag can't be cleared by this function but it is cleared automatically by hardware.
kStatus_SuccessStatus in the mask are cleared.
void UART_EnableInterrupts ( UART_Type *  base,
uint32_t  mask 
)

This function enables the UART interrupts according to the provided mask. The mask is a logical OR of enumeration members. See _uart_interrupt_enable. For example, to enable TX empty interrupt and RX full interrupt:

Parameters
baseUART peripheral base address.
maskThe interrupts to enable. Logical OR of _uart_interrupt_enable.
void UART_DisableInterrupts ( UART_Type *  base,
uint32_t  mask 
)

This function disables the UART interrupts according to the provided mask. The mask is a logical OR of enumeration members. See _uart_interrupt_enable. For example, to disable TX empty interrupt and RX full interrupt:

Parameters
baseUART peripheral base address.
maskThe interrupts to disable. Logical OR of _uart_interrupt_enable.
uint32_t UART_GetEnabledInterrupts ( UART_Type *  base)

This function gets the enabled UART interrupts. The enabled interrupts are returned as the logical OR value of the enumerators _uart_interrupt_enable. To check specific interrupts enable status, compare the return value with enumerators in _uart_interrupt_enable. For example, to check whether TX empty interrupt is enabled:

uint32_t enabledInterrupts = UART_GetEnabledInterrupts(UART1);
if (kUART_TxDataRegEmptyInterruptEnable & enabledInterrupts)
{
...
}
Parameters
baseUART peripheral base address.
Returns
UART interrupt flags which are logical OR of the enumerators in _uart_interrupt_enable.
static void UART_EnableTx ( UART_Type *  base,
bool  enable 
)
inlinestatic

This function enables or disables the UART transmitter.

Parameters
baseUART peripheral base address.
enableTrue to enable, false to disable.
static void UART_EnableRx ( UART_Type *  base,
bool  enable 
)
inlinestatic

This function enables or disables the UART receiver.

Parameters
baseUART peripheral base address.
enableTrue to enable, false to disable.
static void UART_WriteByte ( UART_Type *  base,
uint8_t  data 
)
inlinestatic

This function writes data to the TX register directly. The upper layer must ensure that the TX register is empty or TX FIFO has empty room before calling this function.

Parameters
baseUART peripheral base address.
dataThe byte to write.
static uint8_t UART_ReadByte ( UART_Type *  base)
inlinestatic

This function reads data from the TX register directly. The upper layer must ensure that the RX register is full or that the TX FIFO has data before calling this function.

Parameters
baseUART peripheral base address.
Returns
The byte read from UART data register.
void UART_WriteBlocking ( UART_Type *  base,
const uint8_t *  data,
size_t  length 
)

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.

Note
This function does not check whether all the data has been sent out to the bus. Before disabling the TX, check kUART_TransmissionCompleteFlag to ensure that the TX is finished.
Parameters
baseUART peripheral base address.
dataStart address of the data to write.
lengthSize of the data to write.
status_t UART_ReadBlocking ( UART_Type *  base,
uint8_t *  data,
size_t  length 
)

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.

Parameters
baseUART peripheral base address.
dataStart address of the buffer to store the received data.
lengthSize of the buffer.
Return values
kStatus_UART_RxHardwareOverrunReceiver overrun happened while receiving data.
kStatus_UART_NoiseErrorNoise error happened while receiving data.
kStatus_UART_FramingErrorFraming error happened while receiving data.
kStatus_UART_ParityErrorParity error happened while receiving data.
kStatus_SuccessSuccessfully received all data.
void UART_TransferCreateHandle ( UART_Type *  base,
uart_handle_t *  handle,
uart_transfer_callback_t  callback,
void *  userData 
)

This function initializes the UART handle which can be used for other UART transactional APIs. Usually, for a specified UART instance, call this API once to get the initialized handle.

Parameters
baseUART peripheral base address.
handleUART handle pointer.
callbackThe callback function.
userDataThe parameter of the callback function.
void UART_TransferStartRingBuffer ( UART_Type *  base,
uart_handle_t *  handle,
uint8_t *  ringBuffer,
size_t  ringBufferSize 
)

This function sets up the RX ring buffer to a specific UART handle.

When the RX ring buffer is used, data received are stored into the ring buffer even when the user doesn't call the UART_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 ringBufferSize is 32, then only 31 bytes are used for saving data.
Parameters
baseUART peripheral base address.
handleUART handle pointer.
ringBufferStart address of the ring buffer for background receiving. Pass NULL to disable the ring buffer.
ringBufferSizesize of the ring buffer.
void UART_TransferStopRingBuffer ( UART_Type *  base,
uart_handle_t *  handle 
)

This function aborts the background transfer and uninstalls the ring buffer.

Parameters
baseUART peripheral base address.
handleUART handle pointer.
status_t UART_TransferSendNonBlocking ( UART_Type *  base,
uart_handle_t *  handle,
uart_transfer_t xfer 
)

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 ISR, the UART driver calls the callback function and passes the kStatus_UART_TxIdle as status parameter.

Note
The kStatus_UART_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 kUART_TransmissionCompleteFlag to ensure that the TX is finished.
Parameters
baseUART peripheral base address.
handleUART handle pointer.
xferUART transfer structure. See uart_transfer_t.
Return values
kStatus_SuccessSuccessfully start the data transmission.
kStatus_UART_TxBusyPrevious transmission still not finished, data not all written to TX register yet.
kStatus_InvalidArgumentInvalid argument.
void UART_TransferAbortSend ( UART_Type *  base,
uart_handle_t *  handle 
)

This function aborts the interrupt driven data sending. The user can get the remainBytes to find out how many bytes are still not sent out.

Parameters
baseUART peripheral base address.
handleUART handle pointer.
status_t UART_TransferGetSendCount ( UART_Type *  base,
uart_handle_t *  handle,
uint32_t *  count 
)

This function gets the number of bytes that have been written to UART TX register by interrupt method.

Parameters
baseUART peripheral base address.
handleUART handle pointer.
countSend bytes count.
Return values
kStatus_NoTransferInProgressNo send in progress.
kStatus_InvalidArgumentParameter is invalid.
kStatus_SuccessGet successfully through the parameter count;
status_t UART_TransferReceiveNonBlocking ( UART_Type *  base,
uart_handle_t *  handle,
uart_transfer_t xfer,
size_t *  receivedBytes 
)

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 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 UART driver. When the new data arrives, the receive request is serviced first. When all data is received, the UART driver notifies the upper layer through a callback function and passes the status parameter kStatus_UART_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 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 UART 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.

Parameters
baseUART peripheral base address.
handleUART handle pointer.
xferUART transfer structure, refer to uart_transfer_t.
receivedBytesBytes received from the ring buffer directly.
Return values
kStatus_SuccessSuccessfully queue the transfer into transmit queue.
kStatus_UART_RxBusyPrevious receive request is not finished.
kStatus_InvalidArgumentInvalid argument.
void UART_TransferAbortReceive ( UART_Type *  base,
uart_handle_t *  handle 
)

This function aborts the interrupt-driven data receiving. The user can get the remainBytes to know how many bytes not received yet.

Parameters
baseUART peripheral base address.
handleUART handle pointer.
status_t UART_TransferGetReceiveCount ( UART_Type *  base,
uart_handle_t *  handle,
uint32_t *  count 
)

This function gets the number of bytes that have been received.

Parameters
baseUART peripheral base address.
handleUART handle pointer.
countReceive bytes count.
Return values
kStatus_NoTransferInProgressNo receive in progress.
kStatus_InvalidArgumentParameter is invalid.
kStatus_SuccessGet successfully through the parameter count;
void UART_TransferHandleIRQ ( UART_Type *  base,
uart_handle_t *  handle 
)

This function handles the UART transmit and receive IRQ request.

Parameters
baseUART peripheral base address.
handleUART handle pointer.
void UART_TransferHandleErrorIRQ ( UART_Type *  base,
uart_handle_t *  handle 
)

This function handle the UART error IRQ request.

Parameters
baseUART peripheral base address.
handleUART handle pointer.