Overview

The MCUXpresso SDK provides a peripheral driver for the Low Power UART (UART) module of MCUXpresso SDK devices.

Typical use case

UART Operation

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/uart

Data Structures
struct	uart_fifo_config_t
	UART FIFO Configuration Structure definition. More...

struct	uart_autobaud_config_t
	UART Auto baud detect and set Configuration Structure definition. More...

struct	uart_infrared_config_t
	UART Infrared Configuration Structure type definition. More...

struct	uart_config_t
	UART configuration structure. More...

struct	uart_handle_t
	UART transfer handle. More...

struct	uart_transfer_t
	UART transfer structure. More...

Macros
#define	UART_RETRY_TIMES 0U /* Defining to zero means to keep waiting for the flag until it is asserts/deasserts. */
	Retry times for waiting flag. More...

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

Enumerations
enum	{ 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_FlagCannotClearManually = MAKE_STATUS(kStatusGroup_UART, 4), kStatus_UART_Error = MAKE_STATUS(kStatusGroup_UART, 5), kStatus_UART_RxRingBufferOverrun = MAKE_STATUS(kStatusGroup_UART, 6), kStatus_UART_RxHardwareOverrun = MAKE_STATUS(kStatusGroup_UART, 7), kStatus_UART_FifoError = MAKE_STATUS(kStatusGroup_UART, 8), kStatus_UART_FramingError = MAKE_STATUS(kStatusGroup_UART, 9), kStatus_UART_ParityError = MAKE_STATUS(kStatusGroup_UART, 10), kStatus_UART_BaudrateNotSupport, kStatus_UART_IdleLineDetected = MAKE_STATUS(kStatusGroup_UART, 12), kStatus_UART_Timeout = MAKE_STATUS(kStatusGroup_UART, 13), kStatus_UART_RxFifoError = MAKE_STATUS(kStatusGroup_UART, 14) }
	Error codes for the UART driver. More...

enum	_uart_interrupt_enable { kUART_RxDataReadyInterruptEnable, kUART_TxDataRequestInterruptEnable, kUART_RxStatusInterruptEnable, kUART_ModemStatusChangeInterruptEnable, kUART_RxTimeoutInterruptEnable = (UART_IER_RTOIE_MASK), kUART_AutoBaudCompleteInterruptEnable }
	UART interrupt configuration structure, default settings all disabled. More...

enum	_uart_status_flags { kUART_RxDataReadyInterruptFlag, kUART_RxOverrunInterruptFlag = (UART_LSR_OE_MASK), kUART_ParityErrorInterruptFlag = (UART_LSR_PE_MASK), kUART_FramingErrorInterruptFLag, kUART_BreakDetectInterruptFlag = (UART_LSR_BI_MASK), kUART_TxDataRequestInterruptFlag, kUART_TxEmptyInterruptFlag, kUART_FifoErrorInterruptFlag, kUART_RxTimeoutInterruptFlag = (UART_IIR_TOD_MASK << 8), kUART_AutoBaudCompleteInterruptFlag }
	UART status flags. More...

enum	uart_parity_mode_t { kUART_ParityDisabled = 0x0U, kUART_ParityOdd = 0x1U, kUART_ParityEven = 0x2U }
	UART parity mode. More...

enum	uart_data_bits_t { kUART_Databits5 = 0x0U, kUART_Databits6, kUART_Databits7, kUART_Databits8 }
	UART data bits count. More...

enum	uart_stop_bit_count_t { kUART_Stopbits1, kUART_Stopbits2 }
	UART stop bit count. More...

enum	uart_txfifo_watermark_t { kUART_TxfifoHalfEmpty = 0U, kUART_TxfifoEmpty }
	UART TX FIFO watermark level definition. More...

enum	uart_rxfifo_watermark_t { kUART_RxfifoByte1 = 0U, kUART_RxfifoBytes8, kUART_RxfifoBytes16, kUART_RxfifoBytes32 }
	UART RX FIFO watermark level definition. More...

enum	uart_autobaud_program_t { kUART_BaudrateProgramManual = 0, kUART_BaudrateProgramAuto }
	UART Auto Baud Calculation type definition. More...

enum	uart_autobaud_calculation_t { kUART_BaudrateCalFormula = 0, kUART_BaudrateCalTable }
	UART Auto Baud Calculation type definition. More...

enum	uart_infrared_polarity_t { kUART_IrPositivePulse = 0, kUART_IrNegativePulse }
	UART Infrared mode ncoder/Decoder Polarity type definition. More...

enum	uart_infrared_pulsewidth_t { kUART_IrPulsewidth3div16 = 0, kUART_IrPulsewidth1p6us }
	UART Infrared Transmit Pulse Width type definition. More...

Functions
uint32_t	UART_GetInstance (UART_Type *base)
	Get the UART instance from peripheral base address. More...

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

Initialization and deinitialization
status_t	UART_Init (UART_Type base, const uart_config_t config, uint32_t srcClock_Hz)
	Initializes an UART instance with the user configuration structure and the peripheral clock frequency. 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...

Hardware Status Flags
uint16_t	UART_GetStatusFlags (UART_Type *base)
	Gets UART hardware status flags. More...

Interrupt
void	UART_EnableInterrupts (UART_Type *base, uint8_t interrupts)
	Enables UART interrupts according to the provided mask. More...

void	UART_DisableInterrupts (UART_Type *base, uint8_t interrupts)
	Disables UART interrupts according to the provided mask. More...

uint8_t	UART_GetEnabledInterrupts (UART_Type *base)
	Gets the enabled UART interrupts. More...

General Peripheral Configuration
static void	UART_Enable (UART_Type *base, bool enable)
	Enables or disables the UART module. More...

static void	UART_EnableHighSpeed (UART_Type *base, bool enable)
	Enables or disables the UART high speed mode. More...

static void	UART_EnableDMA (UART_Type *base, bool enable)
	Enables or disables the UART dma request. More...

static void	UART_SetFifoConfig (UART_Type base, uart_fifo_config_t fifoConfig)
	Set the UART FIFO configuration. More...

static bool	UART_IsFifoEnabled (UART_Type *base)
	Checks the UART FIFO enable status. More...

static void	UART_EnablCts (UART_Type *base, bool enable)
	Enables or disables the UART CTS input. More...

static void	UART_EnableRts (UART_Type *base, bool enable)
	Enables or disables the UART RTS output. More...

static bool	UART_IsCtsAsserted (UART_Type *base)
	Checks the CTS pin status. More...

static void	UART_EnableLoop (UART_Type *base, bool enable)
	Enables or disables the UART loop mode. More...

static void	UART_SetParity (UART_Type *base, uart_parity_mode_t parity)
	Set the UART parity type. More...

static void	UART_EnableStickyParity (UART_Type *base, bool enable)
	Enables or disables sticky parity. More...

static void	UART_SetDataBits (UART_Type *base, uart_data_bits_t dataBits)
	Set the UART data bits. More...

static void	UART_SetStopBits (UART_Type *base, uart_stop_bit_count_t stopBits)
	Set the UART stop bits. More...

static uint8_t	UART_GetRxFifoLevel (UART_Type *base)
	Get current UART receive FIFO level. More...

status_t	UART_SetBaudRate (UART_Type *base, uint32_t baudRate_Bps, uint32_t srcClock_Hz)
	Sets the UART instance baudrate. More...

void	UART_SetAutoBaudConfig (UART_Type base, uart_autobaud_config_t autoBaudConfig)
	Sets the UART auto baud configuration. More...

static uint16_t	UART_GetAutoBaudCount (UART_Type *base)
	Get UART auto baud count number. More...

void	UART_SetAutoBaud (UART_Type *base)
	Set DL register according to Auto Baud Detect Count value. More...

void	UART_SetInfraredConfig (UART_Type base, uart_infrared_config_t infraredConfig)
	Sets the UART auto baud configuration. More...

Bus Operation
static uint32_t	UART_GetRxDataRegisterAddress (UART_Type *base)
	Gets the UART receive data register byte address. More...

static uint32_t	UART_GetTxDataRegisterAddress (UART_Type *base)
	Gets the UART transmit data register byte address. 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...

static void	UART_Write9bits (UART_Type *base, uint16_t data)
	Send 9 bit data to the UART peripheral. More...

uint16_t	UART_Read9bits (UART_Type *base)
	Read 9 bit data from the UART peripheral. More...

status_t	UART_WriteBlocking (UART_Type base, const uint8_t data, uint32_t length)
	Writes TX register using a blocking method. More...

status_t	UART_ReadBlocking (UART_Type base, uint8_t data, uint32_t length)
	Reads RX data register using a blocking method. More...

static void	UART_EnableBreakCondition (UART_Type *base, bool enable)
	Enables or disables break condition. 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...

size_t	UART_TransferGetRxRingBufferLength (UART_Type base, uart_handle_t handle)
	Get the length of received data in RX 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...

status_t	UART_TransferGetSendCount (UART_Type base, uart_handle_t handle, uint32_t *count)
	Gets the number of bytes that have been sent out to bus. More...

void	UART_TransferAbortSend (UART_Type base, uart_handle_t handle)
	Aborts the interrupt-driven data transmit. 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 the interrupt method. More...

status_t	UART_TransferGetReceiveCount (UART_Type base, uart_handle_t handle, uint32_t *count)
	Gets the number of bytes that have been received. More...

void	UART_TransferAbortReceive (UART_Type base, uart_handle_t handle)
	Aborts the interrupt-driven data receiving. 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_fifo_config_t

Data Fields
uart_txfifo_watermark_t	txFifoWatermark
	TX FIFO watermark. More...

uart_rxfifo_watermark_t	rxFifoWatermark
	RX FIFO watermark. More...

bool	resetTxFifo
	Tx FIFO reset. More...

bool	resetRxFifo
	Rx FIFO reset. More...

bool	fifoEnable
	FIFO enable. More...

Field Documentation

uart_txfifo_watermark_t uart_fifo_config_t::txFifoWatermark

FCR[TIL]

uart_rxfifo_watermark_t uart_fifo_config_t::rxFifoWatermark

FCR[ITL]

bool uart_fifo_config_t::resetTxFifo

FCR[RESETTF]

bool uart_fifo_config_t::resetRxFifo

FCR[RESETRF]

bool uart_fifo_config_t::fifoEnable

FCR[TRFIFOE]

struct uart_autobaud_config_t

Data Fields
bool	autoBaudEnable
	Enable or Disable Auto Baud Function. More...

uart_autobaud_program_t	baudProgramType
	Uart Auto Baud Program type. More...

uart_autobaud_calculation_t	baudCalType
	Uart Auto Baud calculation type. More...

Field Documentation

bool uart_autobaud_config_t::autoBaudEnable

ABR[ABE]

uart_autobaud_program_t uart_autobaud_config_t::baudProgramType

ABR[ABUP]

uart_autobaud_calculation_t uart_autobaud_config_t::baudCalType

ABR[ABT]

struct uart_infrared_config_t

Data Fields
bool	txIrEnable
	Enable or Disable Uart Transmit IR Function. More...

bool	rxIrEnable
	Enable or Disable Uart Receive IR Function. More...

uart_infrared_polarity_t	txIrPolarity
	Transmit IR Polarity type. More...

uart_infrared_polarity_t	rxIrPolarity
	Receive IR Polarity type. More...

uart_infrared_pulsewidth_t	irPulseWidth
	IR Pulse Width type. More...

Field Documentation

bool uart_infrared_config_t::txIrEnable

ISR[XMITIR]

bool uart_infrared_config_t::rxIrEnable

ISR[RCVEIR]

uart_infrared_polarity_t uart_infrared_config_t::txIrPolarity

ISR[TXPL]

uart_infrared_polarity_t uart_infrared_config_t::rxIrPolarity

ISR[RXPL]

uart_infrared_pulsewidth_t uart_infrared_config_t::irPulseWidth

ISR[XMODE]

struct uart_config_t

Data Fields
uint32_t	baudRate_Bps
	UART baud rate. More...

uart_parity_mode_t	parityMode
	Parity mode, disabled (default), even, odd. More...

bool	enableStickyParity
	Sticky parity, when enabled the parity bit remains unchanged and is opposite to PEN bit. More...

uart_data_bits_t	dataBitCount
	Data bits count, eight (default), seven. More...

uart_stop_bit_count_t	stopBitCount
	Number of stop bits, 1 stop bit (default) or 2 stop bits. More...

uart_fifo_config_t	fifoConfig
	FIFO configuration. More...

uart_autobaud_config_t	autoBaudConfig
	Auto baud detect and set configuration. More...

uart_infrared_config_t	infraredConfig
	Infrared function configuration. More...

bool	enableHighSpeed
	High speed enable. More...

bool	enableLoop
	Loop mode MCR[LOOP].

bool	enableTxCTS
	TX CTS enable. More...

bool	enableRxRTS
	RX RTS enable. More...

bool	enable
	Enable UART. More...

Field Documentation

uint32_t uart_config_t::baudRate_Bps

DLL, DLH

uart_parity_mode_t uart_config_t::parityMode

LCR[EPS][PEN]

bool uart_config_t::enableStickyParity

LCR[STKYP]

uart_data_bits_t uart_config_t::dataBitCount

LCR[WLS10]

uart_stop_bit_count_t uart_config_t::stopBitCount

LCR[STB]

uart_fifo_config_t uart_config_t::fifoConfig

uart_autobaud_config_t uart_config_t::autoBaudConfig

uart_infrared_config_t uart_config_t::infraredConfig

bool uart_config_t::enableHighSpeed

IER[HSE] = 1

bool uart_config_t::enableTxCTS

MCR[AFE] = 1

bool uart_config_t::enableRxRTS

To enable RTS, CTS must be enabled. MCR[AFE][RTS] = 11

bool uart_config_t::enable

IER[UUE]

struct _uart_handle_t

Note: If user wants to use the transactional API to transfer data in interrupt way, one UART instance should and can only be allocated one handle.; The handle is maintained by UART driver internally, which means the transfer state is retained and user shall not modify its state txState or rxState in application level. If user only wish to use transactional APIs without understanding its machanism, it is not necessary to understand these members.

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. More...

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

volatile uint8_t uart_handle_t::rxState

struct uart_transfer_t

Data Fields
uint8_t *	data
	The buffer pointer of data to be transferred. More...

uint32_t	dataSize
	The byte count to be transferred. More...

Field Documentation

uint8_t* uart_transfer_t::data

uint32_t uart_transfer_t::dataSize

Macro Definition Documentation

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

#define UART_RETRY_TIMES 0U /* Defining to zero means to keep waiting for the flag until it is asserts/deasserts. */

Typedef Documentation

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

Defines the interface of user callback function used in UART interrupt transfer using transactional APIs. The callback function shall be defined and declared in application level by user. Before starting UART transmiting or receiving by calling UART_TransferSendNonBlocking or UART_TransferReceiveNonBlocking, call UART_TransferCreateHandle to install the user callback. When the transmiting or receiving ends or any bus error like hardware overrun occurs, user callback will be invoked by driver.

Parameters

base	UART peripheral base address.
handle	Transfer handle.
status	Transfer status
userData	Pointer to user specified data or structure etc.

Enumeration Type Documentation

anonymous enum

Enumerator
kStatus_UART_TxBusy	TX busy.
kStatus_UART_RxBusy	RX busy.
kStatus_UART_TxIdle	UART transmitter is idle.
kStatus_UART_RxIdle	UART receiver is idle.
kStatus_UART_FlagCannotClearManually	Some flag can't manually clear.
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_FifoError	UART noise error.
kStatus_UART_FramingError	UART framing error.
kStatus_UART_ParityError	UART parity error.
kStatus_UART_BaudrateNotSupport	Baudrate is not support in current clock source.
kStatus_UART_IdleLineDetected	IDLE flag.
kStatus_UART_Timeout	UART times out.
kStatus_UART_RxFifoError	UART Rx FIFO error.

enum _uart_interrupt_enable

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

Enumerator
kUART_RxDataReadyInterruptEnable	Receiver data ready interrupt, caused by rx register full when FIFO disabled or rx data count above water mark when FIFO enabled. bit 0
kUART_TxDataRequestInterruptEnable	Transmitter data request interrupt, caused by tx register empty when FIFO disabled or tx data count below water mark when FIFO enabled. bit 1
kUART_RxStatusInterruptEnable	Receiver line status interrupt, caused by such status as rx over run, framing/parity error and break detect. bit 2
kUART_ModemStatusChangeInterruptEnable	Modem status change interrupt, caused by RTS/CTS pin status change. bit 3
kUART_RxTimeoutInterruptEnable	Receiver timeout interrupt. bit 4
kUART_AutoBaudCompleteInterruptEnable	Auto baud completes programing baud rate divisor interrupt. bit 5

enum _uart_status_flags

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

Enumerator
kUART_RxDataReadyInterruptFlag	Receiver data ready flag, self cleared by reading data out. bit 0
kUART_RxOverrunInterruptFlag	Receiver overrun flag, can cause rx status interrupt, slef cleared when reading the LSR(line status register). bit 1
kUART_ParityErrorInterruptFlag	Parity error flag, can cause rx status interrupt, self cleared when reading the LSR(line status register). bit 2
kUART_FramingErrorInterruptFLag	Framing error flag, can cause rx status interrupt, self cleared when reading the LSR(line status register). bit 3
kUART_BreakDetectInterruptFlag	Break detect flag, can cause rx status interrupt, self cleared when reading the LSR(line status register). bit 4
kUART_TxDataRequestInterruptFlag	Transmitter data request flag, self cleared by pushing data to tx FIFO until data count exceed water mark. bit 5
kUART_TxEmptyInterruptFlag	Transmitter empty flag, self cleared by pushing data to tx FIFO. bit 6
kUART_FifoErrorInterruptFlag	FIFO error flag, self cleared by empting the rx FIFO. bit 7
kUART_RxTimeoutInterruptFlag	Receiver timeout interrupt flag. bit 11
kUART_AutoBaudCompleteInterruptFlag	Auto baud completes programing baud rate divisor flag. bit 12

enum uart_parity_mode_t

Enumerator
kUART_ParityDisabled	Parity disabled, bit setting: LCR[PEN] = 0.
kUART_ParityOdd	Parity enabled, type odd, bit setting: LCR[EPS]\|[PEN] = 01.
kUART_ParityEven	Parity enabled, type even, bit setting: LCR[EPS]\|[PEN] = 11.

enum uart_data_bits_t

Enumerator
kUART_Databits5	UART data bits length: 5 bits.
kUART_Databits6	UART data bits length: 6 bits.
kUART_Databits7	UART data bits length: 7 bits.
kUART_Databits8	UART data bits length: 8 bits.

enum uart_stop_bit_count_t

Enumerator
kUART_Stopbits1	UART stop bits length: 1 bits.
kUART_Stopbits2	UART stop bits length: 2 bits.

enum uart_txfifo_watermark_t

Enumerator
kUART_TxfifoHalfEmpty	UART Transmit Interrupt Level: half empty.
kUART_TxfifoEmpty	UART Transmit Interrupt Level: full empty.

enum uart_rxfifo_watermark_t

Enumerator
kUART_RxfifoByte1	1 byte or more in rx fifo causes interrupt(Not valid in dma mode)
kUART_RxfifoBytes8	8 byte or more in rx fifo causes interrupt
kUART_RxfifoBytes16	16 byte or more in rx fifo causes interrupt
kUART_RxfifoBytes32	32 byte or more in rx fifo causes interrupt

enum uart_autobaud_program_t

Enumerator
kUART_BaudrateProgramManual	User calculates and programs UART divisor latch register using the value UART stored in Auto-Baud Count Register.
kUART_BaudrateProgramAuto	UART programs UART Divisor Latch Register automatically.

enum uart_autobaud_calculation_t

When choosing kUART_BaudrateProgramAuto for baud rate program method, this is used to configure the baudrate calculation method of UART.

Enumerator

kUART_BaudrateCalFormula

Formula is used to calculate baud rate, any baud rate can be programmed by the UART but could fail below 28.8 Kbps.

kUART_BaudrateCalTable

Table is used to calculate baud rate, allows any baud rate above 28.8 Kbps.

Below 28.8 Kbps the only baud rates that can be programmed by the UART are 19200, 14400, 9600, 4800, 1200, and 300.

enum uart_infrared_polarity_t

Enumerator
kUART_IrPositivePulse	UART IR Encoder/Decoder takes positive pulse as zero.
kUART_IrNegativePulse	UART IR Encoder/Decoder takes negative pulse as zero.

enum uart_infrared_pulsewidth_t

Enumerator
kUART_IrPulsewidth3div16	UART IR Transmit pulse width is 3/16 of a bit time width.
kUART_IrPulsewidth1p6us	UART IR Transmit pulse width is 1.6us width.

Function Documentation

uint32_t UART_GetInstance ( UART_Type * base )

Parameters

base	UART peripheral base address.

Returns: UART instance.

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

This function configures the UART module with user-defined settings. Call the UART_GetDefaultConfig function to get the configuration structure configured with default settings. The example below shows how to use this API to configure the UART.

*  uart_config_t uartConfig;
*  UART_GetDefaultConfig(&uartConfig);
*  UART_Init(UART1, &uartConfig, 20000000U);
* 

Parameters

base	UART peripheral base address.
config	Pointer to a user-defined configuration structure.
srcClock_Hz	UART clock source frequency in Hz.

Return values

kStatus_UART_BaudrateNotSupport	Baudrate is not support in current clock source.
kStatus_Success	UART initialize succeed

void UART_Deinit ( UART_Type * base )

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

Parameters

base	UART peripheral base address.

void UART_GetDefaultConfig ( uart_config_t * config )

This function initializes the UART configuration structure to a default value. The example below shows how to use this API to configure the UART.

*  uart_config_t uartConfig;
*  UART_GetDefaultConfig(&uartConfig);
*  UART_Init(UART1, &uartConfig, 20000000U);
* 

Parameters

config Pointer to a configuration structure.

uint16_t UART_GetStatusFlags ( UART_Type * base )

Parameters

base	UART peripheral base address.

Returns: UART status flags, can be a single flag or several flags in _uart_status_flags combined by OR.

void UART_EnableInterrupts	(	UART_Type *	base,
		uint8_t	interrupts
	)

This function enables the UART interrupts according to the provided mask. The mask is a logical OR of enumeration members in _uart_interrupt_enable.

Parameters

base	UART peripheral base address.
interrupts	The interrupt source mask, can be a single source or several sources in _uart_interrupt_enable combined by OR.

void UART_DisableInterrupts	(	UART_Type *	base,
		uint8_t	interrupts
	)

This function disables the UART interrupts according to the provided mask. The mask is a logical OR of enumeration members in _uart_interrupt_enable.

Parameters

base	UART peripheral base address.
interrupts	The interrupt source mask, can be a single source or several sources in _uart_interrupt_enable combined by OR.

uint8_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.

Parameters

base	UART peripheral base address.

Returns: The interrupt source mask, can be a single source or several sources in _uart_interrupt_enable combined by OR.

static void UART_Enable	(	UART_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	UART peripheral base address.
enable	True to enable, false to disable.

static void UART_EnableHighSpeed	(	UART_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	UART peripheral base address.
enable	True to enable, false to disable.

static void UART_EnableDMA	(	UART_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	UART peripheral base address.
enable	True to enable, false to disable.

static void UART_SetFifoConfig	(	UART_Type *	base,
		uart_fifo_config_t *	fifoConfig
	)

inlinestatic

Note: The FIFO configuration register FCR is write only, so we have no way of getting current FIFO configuration. In this case any modification of FCR must contain the full FIFO configuration, including tx/rx watermark, whether to reset tx/rx FIFO, and tx/rx FIFO enable.

Parameters

base	UART peripheral base address
fifoConfig	Pointer to FIFO configuration structure

static bool UART_IsFifoEnabled ( UART_Type * base )

inlinestatic

Parameters

base	UART peripheral base address.

Returns: true is FIFO is enabled.

static void UART_EnablCts	(	UART_Type *	base,
		bool	enable
	)

inlinestatic

Note: The RTS output can not be enabled without enabling the CTS input, which means disabling CTS will disables RTS as well.

Parameters

base	UART peripheral base address.
enable	True to enable, false to disable.

static void UART_EnableRts	(	UART_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	UART peripheral base address.
enable	True to enable, false to disable.

static bool UART_IsCtsAsserted ( UART_Type * base )

inlinestatic

Parameters

base	UART peripheral base address.

Returns: true is CTS pin is asserted meaning free to send data.

static void UART_EnableLoop	(	UART_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	UART peripheral base address.
enable	True to enable, false to disable.

static void UART_SetParity	(	UART_Type *	base,
		uart_parity_mode_t	parity
	)

inlinestatic

Parameters

base	UART peripheral base address.
parity	parity type

static void UART_EnableStickyParity	(	UART_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	UART peripheral base address.
enable	True to enable, false to disable.

static void UART_SetDataBits	(	UART_Type *	base,
		uart_data_bits_t	dataBits
	)

inlinestatic

Parameters

base	UART peripheral base address.
dataBits	bits to set

static void UART_SetStopBits	(	UART_Type *	base,
		uart_stop_bit_count_t	stopBits
	)

inlinestatic

Parameters

base	UART peripheral base address.
stopBits	stop bits to set

static uint8_t UART_GetRxFifoLevel ( UART_Type * base )

inlinestatic

Parameters

base	Select the UART port, should be kUART1_Id, kUART2_Id.

Returns: The number of data entries in the receive FIFO

status_t UART_SetBaudRate	(	UART_Type *	base,
		uint32_t	baudRate_Bps,
		uint32_t	srcClock_Hz
	)

This API configures the UART module baudrate. This API can be used to update the UART module baudrate after the UART module is initialized by the UART_Init.

* UART_SetBaudRate(UART1, 115200U, 20000000U);

*

Parameters

base	UART peripheral base address.
baudRate_Bps	UART baudrate to be set.
srcClock_Hz	UART clock source frequency in HZ.

Return values

kStatus_UART_BaudrateNotSupport	Baudrate is not supported in the current clock source.
kStatus_Success	Set baudrate succeeded.

void UART_SetAutoBaudConfig	(	UART_Type *	base,
		uart_autobaud_config_t *	autoBaudConfig
	)

This API configures the UART auto baud function, including enable/disable, calculation type, program type.

Parameters

base	UART peripheral base address.
autoBaudConfig	pointer to UART auto baud configuration.

static uint16_t UART_GetAutoBaudCount ( UART_Type * base )

inlinestatic

Parameters

base	UART peripheral base address

Returns: none

void UART_SetAutoBaud ( UART_Type * base )

Parameters

base	UART peripheral base address.

void UART_SetInfraredConfig	(	UART_Type *	base,
		uart_infrared_config_t *	infraredConfig
	)

This API configures the UART auto baud function, including enable/disable, calculation type, program type.

Parameters

base	UART peripheral base address.
infraredConfig	pointer to UART infrared configuration.

static uint32_t UART_GetRxDataRegisterAddress ( UART_Type * base )

inlinestatic

This function returns the UART receive data register address, which is mainly used by DMA/eDMA.

Parameters

base	UART peripheral base address.

Returns: UART data register byte addresses which are used both by the transmitter and the receiver.

static uint32_t UART_GetTxDataRegisterAddress ( UART_Type * base )

inlinestatic

This function returns the UART transmit data register address, which is mainly used by DMA/eDMA.

Parameters

base	UART peripheral base address.

Returns: UART data register byte addresses which are used both by the transmitter and the receiver.

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 room before calling this function.

Parameters

base	UART peripheral base address.
data	The byte to write.

static uint8_t UART_ReadByte ( UART_Type * base )

inlinestatic

This function reads data from the RX 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

base	UART peripheral base address.

Returns: The byte read from UART data register.

static void UART_Write9bits	(	UART_Type *	base,
		uint16_t	data
	)

inlinestatic

Before calling this API, make sure parity and sticky parity are enabled, and tx register empty or room in tx FIFO.

Parameters

base	UART peripheral base address.
data	The data to be sent

uint16_t UART_Read9bits ( UART_Type * base )

Before calling this API, make sure parity is enabled, and rx register full or data available in rx FIFO.

Parameters

base	UART peripheral base address.

Returns: The received data

status_t UART_WriteBlocking	(	UART_Type *	base,
		const uint8_t *	data,
		uint32_t	length
	)

This function polls the TX register, waits TX register to be empty or TX FIFO have room then writes data to the TX buffer.

Parameters

base	UART peripheral base address.
data	Start address of the data to write.
length	Size of the data to write.

status_t UART_ReadBlocking	(	UART_Type *	base,
		uint8_t *	data,
		uint32_t	length
	)

This function polls the RX register, waits RX register to be full or RX FIFO have data, then reads data from the RX register.

Parameters

base	UART peripheral base address.
data	Start address of the buffer to store the received data.
length	Size of the buffer.

Return values

kStatus_Fail	Receiver error occurred while receiving data.
kStatus_UART_RxHardwareOverrun	Receiver overrun occurred while receiving data
kStatus_UART_NoiseError	Noise error occurred while receiving data
kStatus_UART_FramingErrorFraming	error occurred while receiving data
kStatus_UART_ParityError	Parity error occurred while receiving data
kStatus_Success	Successfully received all data.

static void UART_EnableBreakCondition	(	UART_Type *	base,
		bool	enable
	)

inlinestatic

When break condition is enabled tx pin is pulled low by UART, when disabled the pin is high.

Parameters

base	UART peripheral base address.
enable	True to enable, false to disable.

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.

The UART driver supports the "background" receiving, which means that user can set up an RX ring buffer optionally. Data received is 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. The ring buffer is disabled if passing NULL as ringBuffer.

Parameters

base	UART peripheral base address.
handle	UART handle pointer.
callback	Callback function.
userData	User data.

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 is 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 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

base	UART peripheral base address.
handle	UART handle pointer.
ringBuffer	Start address of ring buffer for background receiving. Pass NULL to disable the ring buffer.
ringBufferSize	size 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

base	UART peripheral base address.
handle	UART handle pointer.

size_t UART_TransferGetRxRingBufferLength	(	UART_Type *	base,
		uart_handle_t *	handle
	)

Parameters

base	UART peripheral base address.
handle	UART handle pointer.

Returns: Length of received data in RX ring buffer.

status_t UART_TransferSendNonBlocking	(	UART_Type *	base,
		uart_handle_t *	handle,
		uart_transfer_t *	xfer
	)

This function send data using an interrupt method. This is a non-blocking function, which returns directly without waiting for all data written to the transmitter 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 are written to the TX register. However, there is no check to ensure that all the data sent out. Before disabling the TX, check the kUART_TransmissionCompleteFlag to ensure that the transmit is finished.

Parameters

base	UART peripheral base address.
handle	UART handle pointer.
xfer	UART transfer structure, see uart_transfer_t.

Return values

kStatus_Success	Successfully start the data transmission.
kStatus_UART_TxBusy	Previous transmission still not finished, data not all written to the TX register.
kStatus_InvalidArgument	Invalid argument.

status_t UART_TransferGetSendCount	(	UART_Type *	base,
		uart_handle_t *	handle,
		uint32_t *	count
	)

This function gets the number of bytes that have been sent out to bus by an interrupt method.

Parameters

base	UART peripheral base address.
handle	UART handle pointer.
count	Send bytes count.

Return values

kStatus_NoTransferInProgress	No send in progress.
kStatus_InvalidArgument	Parameter is invalid.
kStatus_Success	Get successfully through the parameter `count`;

void UART_TransferAbortSend	(	UART_Type *	base,
		uart_handle_t *	handle
	)

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

Parameters

base	UART peripheral base address.
handle	UART handle pointer.

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 to ensure that all data are 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 for 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 a status parameter kStatus_UART_RxIdle. For example, the upper layer needs 10 bytes but there are only 5 bytes in ring buffer. The 5 bytes are copied to xfer->data, which returns with the parameter receivedBytes set to 5. For the remaining 5 bytes, the newly arrived data is saved from 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 xfer->data. When all data is received, the upper layer is notified.

Parameters

base	UART peripheral base address.
handle	UART handle pointer.
xfer	UART transfer structure, see uart_transfer_t.
receivedBytes	Bytes received from the ring buffer directly.

Return values

kStatus_Success	Successfully queue the transfer into the transmit queue.
kStatus_UART_RxBusy	Previous receive request is not finished.
kStatus_InvalidArgument	Invalid argument.

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

base	UART peripheral base address.
handle	UART handle pointer.
count	Receive bytes count.

Return values

kStatus_NoTransferInProgress	No receive in progress.
kStatus_InvalidArgument	Parameter is invalid.
kStatus_Success	Get successfully through the parameter `count`;

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 find out how many bytes not received yet.

Parameters

base	UART peripheral base address.
handle	UART handle pointer.

void UART_TransferHandleIRQ	(	UART_Type *	base,
		uart_handle_t *	handle
	)

This function handles the UART transmit and receive IRQ request.

Parameters

base	UART peripheral base address.
handle	UART handle pointer.

void UART_TransferHandleErrorIRQ	(	UART_Type *	base,
		uart_handle_t *	handle
	)

This function handles the UART error IRQ request.

Parameters

base	UART peripheral base address.
handle	UART handle pointer.

Overview

Typical use case

UART Operation

Data Structures

Macros

Typedefs

Enumerations

Functions

Driver version

Initialization and deinitialization

Hardware Status Flags

Interrupt

General Peripheral Configuration

Bus Operation

Transactional

Data Structure Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Macro Definition Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation