Overview

The MCUXpresso SDK provides a peripheral driver for I2S function using Flexible I/O module of MCUXpresso SDK devices.

The FlexIO I2S driver includes functional APIs and transactional APIs.

Functional APIs are feature/property target low level APIs.

Functional APIs can be used for FlexIO I2S initialization/configuration/operation for optimization/customization purpose. Using the functional API requires the knowledge of the FlexIO I2S peripheral and how to organize functional APIs to meet the application requirements. All functional API use the peripheral base address as the first parameter. FlexIO I2S functional operation groups provide the functional APIs set.

Transactional APIs are transaction target high level APIs. The transactional APIs can be used to enable the peripheral and also in the application if the code size and performance of transactional APIs can satisfy requirements. If the code size and performance are critical requirements, see the transactional API implementation and write custom code. All transactional APIs use the sai_handle_t as the first parameter. Initialize the handle by calling the FlexIO_I2S_TransferTxCreateHandle() or FlexIO_I2S_TransferRxCreateHandle() API.

Transactional APIs support asynchronous transfer. This means that the functions FLEXIO_I2S_TransferSendNonBlocking() and FLEXIO_I2S_TransferReceiveNonBlocking() set up an interrupt for data transfer. When the transfer completes, the upper layer is notified through a callback function with the kStatus_FLEXIO_I2S_TxIdle and kStatus_FLEXIO_I2S_RxIdle status.

Typical use case

FlexIO I2S send/receive using an interrupt method

sai_handle_t g_saiTxHandle;
sai_config_t user_config;
sai_transfer_t sendXfer;
volatile bool txFinished;
volatile bool rxFinished;
const uint8_t sendData[] = [......];
void FLEXIO_I2S_UserCallback(sai_handle_t *handle, status_t status, void *userData)
{
    userData = userData;
    if (kStatus_FLEXIO_I2S_TxIdle == status)
    {
        txFinished = true;
    }
}
void main(void)
{
    //...
    FLEXIO_I2S_TxGetDefaultConfig(&user_config);
    FLEXIO_I2S_TxInit(FLEXIO I2S0, &user_config);
    FLEXIO_I2S_TransferTxCreateHandle(FLEXIO I2S0, &g_saiHandle, FLEXIO_I2S_UserCallback, NULL);
    //Configures the SAI format.
    FLEXIO_I2S_TransferTxSetTransferFormat(FLEXIO I2S0, &g_saiHandle, mclkSource, mclk);
    // Prepares to send.
    sendXfer.data = sendData
    sendXfer.dataSize = sizeof(sendData)/sizeof(sendData[0]);
    txFinished = false;
    // Sends out.
    FLEXIO_I2S_TransferSendNonBlocking(FLEXIO I2S0, &g_saiHandle, &sendXfer);
    // Waiting to send is finished.
    while (!txFinished)
    {
    }
    // ...
}

FLEXIO_I2S send/receive using a DMA method

sai_handle_t g_saiHandle;
dma_handle_t g_saiTxDmaHandle;
dma_handle_t g_saiRxDmaHandle;
sai_config_t user_config;
sai_transfer_t sendXfer;
volatile bool txFinished;
uint8_t sendData[] = ...;
void FLEXIO_I2S_UserCallback(sai_handle_t *handle, status_t status, void *userData)
{
    userData = userData;
    if (kStatus_FLEXIO_I2S_TxIdle == status)
    {
        txFinished = true;
    }
}
void main(void)
{
    //...
    FLEXIO_I2S_TxGetDefaultConfig(&user_config);
    FLEXIO_I2S_TxInit(FLEXIO I2S0, &user_config);
    // Sets up the DMA.
    DMAMUX_Init(DMAMUX0);
    DMAMUX_SetSource(DMAMUX0, FLEXIO_I2S_TX_DMA_CHANNEL, FLEXIO_I2S_TX_DMA_REQUEST);
    DMAMUX_EnableChannel(DMAMUX0, FLEXIO_I2S_TX_DMA_CHANNEL);
    DMA_Init(DMA0);
    /* Creates the DMA handle. */
    DMA_TransferTxCreateHandle(&g_saiTxDmaHandle, DMA0, FLEXIO_I2S_TX_DMA_CHANNEL);
    FLEXIO_I2S_TransferTxCreateHandleDMA(FLEXIO I2S0, &g_saiTxDmaHandle, FLEXIO_I2S_UserCallback, NULL);
    // Prepares to send.
    sendXfer.data = sendData
    sendXfer.dataSize = sizeof(sendData)/sizeof(sendData[0]);
    txFinished = false;
    // Sends out.
    FLEXIO_I2S_TransferSendDMA(&g_saiHandle, &sendXfer);
    // Waiting to send is finished.
    while (!txFinished)
    {
    }
    // ...
}

Data Structures
struct	FLEXIO_I2S_Type
	Define FlexIO I2S access structure typedef. More...

struct	flexio_i2s_config_t
	FlexIO I2S configure structure. More...

struct	flexio_i2s_format_t
	FlexIO I2S audio format, FlexIO I2S only support the same format in Tx and Rx. More...

struct	flexio_i2s_transfer_t
	Define FlexIO I2S transfer structure. More...

struct	flexio_i2s_handle_t
	Define FlexIO I2S handle structure. More...

Macros
#define	I2S_RETRY_TIMES 0U /* Define to zero means keep waiting until the flag is assert/deassert. */
	Retry times for waiting flag. More...

#define	FLEXIO_I2S_XFER_QUEUE_SIZE (4U)
	FlexIO I2S transfer queue size, user can refine it according to use case. More...

Typedefs
typedef void(*	flexio_i2s_callback_t )(FLEXIO_I2S_Type base, flexio_i2s_handle_t handle, status_t status, void *userData)
	FlexIO I2S xfer callback prototype.

Enumerations
enum	{ kStatus_FLEXIO_I2S_Idle = MAKE_STATUS(kStatusGroup_FLEXIO_I2S, 0), kStatus_FLEXIO_I2S_TxBusy = MAKE_STATUS(kStatusGroup_FLEXIO_I2S, 1), kStatus_FLEXIO_I2S_RxBusy = MAKE_STATUS(kStatusGroup_FLEXIO_I2S, 2), kStatus_FLEXIO_I2S_Error = MAKE_STATUS(kStatusGroup_FLEXIO_I2S, 3), kStatus_FLEXIO_I2S_QueueFull = MAKE_STATUS(kStatusGroup_FLEXIO_I2S, 4), kStatus_FLEXIO_I2S_Timeout }
	FlexIO I2S transfer status. More...

enum	flexio_i2s_master_slave_t { kFLEXIO_I2S_Master = 0x0U, kFLEXIO_I2S_Slave = 0x1U }
	Master or slave mode. More...

enum	{ kFLEXIO_I2S_TxDataRegEmptyInterruptEnable = 0x1U, kFLEXIO_I2S_RxDataRegFullInterruptEnable = 0x2U }
	_flexio_i2s_interrupt_enable Define FlexIO FlexIO I2S interrupt mask. More...

enum	{ kFLEXIO_I2S_TxDataRegEmptyFlag = 0x1U, kFLEXIO_I2S_RxDataRegFullFlag = 0x2U }
	_flexio_i2s_status_flags Define FlexIO FlexIO I2S status mask. More...

enum	flexio_i2s_sample_rate_t { kFLEXIO_I2S_SampleRate8KHz = 8000U, kFLEXIO_I2S_SampleRate11025Hz = 11025U, kFLEXIO_I2S_SampleRate12KHz = 12000U, kFLEXIO_I2S_SampleRate16KHz = 16000U, kFLEXIO_I2S_SampleRate22050Hz = 22050U, kFLEXIO_I2S_SampleRate24KHz = 24000U, kFLEXIO_I2S_SampleRate32KHz = 32000U, kFLEXIO_I2S_SampleRate44100Hz = 44100U, kFLEXIO_I2S_SampleRate48KHz = 48000U, kFLEXIO_I2S_SampleRate96KHz = 96000U }
	Audio sample rate. More...

enum	flexio_i2s_word_width_t { kFLEXIO_I2S_WordWidth8bits = 8U, kFLEXIO_I2S_WordWidth16bits = 16U, kFLEXIO_I2S_WordWidth24bits = 24U, kFLEXIO_I2S_WordWidth32bits = 32U }
	Audio word width. More...

Driver version
#define	FSL_FLEXIO_I2S_DRIVER_VERSION (MAKE_VERSION(2, 2, 0))
	FlexIO I2S driver version 2.2.0. More...

Initialization and deinitialization
void	FLEXIO_I2S_Init (FLEXIO_I2S_Type base, const flexio_i2s_config_t config)
	Initializes the FlexIO I2S. More...

void	FLEXIO_I2S_GetDefaultConfig (flexio_i2s_config_t *config)
	Sets the FlexIO I2S configuration structure to default values. More...

void	FLEXIO_I2S_Deinit (FLEXIO_I2S_Type *base)
	De-initializes the FlexIO I2S. More...

static void	FLEXIO_I2S_Enable (FLEXIO_I2S_Type *base, bool enable)
	Enables/disables the FlexIO I2S module operation. More...

Status
uint32_t	FLEXIO_I2S_GetStatusFlags (FLEXIO_I2S_Type *base)
	Gets the FlexIO I2S status flags. More...

Interrupts
void	FLEXIO_I2S_EnableInterrupts (FLEXIO_I2S_Type *base, uint32_t mask)
	Enables the FlexIO I2S interrupt. More...

void	FLEXIO_I2S_DisableInterrupts (FLEXIO_I2S_Type *base, uint32_t mask)
	Disables the FlexIO I2S interrupt. More...

DMA Control
static void	FLEXIO_I2S_TxEnableDMA (FLEXIO_I2S_Type *base, bool enable)
	Enables/disables the FlexIO I2S Tx DMA requests. More...

static void	FLEXIO_I2S_RxEnableDMA (FLEXIO_I2S_Type *base, bool enable)
	Enables/disables the FlexIO I2S Rx DMA requests. More...

static uint32_t	FLEXIO_I2S_TxGetDataRegisterAddress (FLEXIO_I2S_Type *base)
	Gets the FlexIO I2S send data register address. More...

static uint32_t	FLEXIO_I2S_RxGetDataRegisterAddress (FLEXIO_I2S_Type *base)
	Gets the FlexIO I2S receive data register address. More...

Bus Operations
void	FLEXIO_I2S_MasterSetFormat (FLEXIO_I2S_Type base, flexio_i2s_format_t format, uint32_t srcClock_Hz)
	Configures the FlexIO I2S audio format in master mode. More...

void	FLEXIO_I2S_SlaveSetFormat (FLEXIO_I2S_Type base, flexio_i2s_format_t format)
	Configures the FlexIO I2S audio format in slave mode. More...

status_t	FLEXIO_I2S_WriteBlocking (FLEXIO_I2S_Type base, uint8_t bitWidth, uint8_t txData, size_t size)
	Sends data using a blocking method. More...

static void	FLEXIO_I2S_WriteData (FLEXIO_I2S_Type *base, uint8_t bitWidth, uint32_t data)
	Writes data into a data register. More...

status_t	FLEXIO_I2S_ReadBlocking (FLEXIO_I2S_Type base, uint8_t bitWidth, uint8_t rxData, size_t size)
	Receives a piece of data using a blocking method. More...

static uint32_t	FLEXIO_I2S_ReadData (FLEXIO_I2S_Type *base)
	Reads a data from the data register. More...

Transactional
void	FLEXIO_I2S_TransferTxCreateHandle (FLEXIO_I2S_Type base, flexio_i2s_handle_t handle, flexio_i2s_callback_t callback, void *userData)
	Initializes the FlexIO I2S handle. More...

void	FLEXIO_I2S_TransferSetFormat (FLEXIO_I2S_Type base, flexio_i2s_handle_t handle, flexio_i2s_format_t *format, uint32_t srcClock_Hz)
	Configures the FlexIO I2S audio format. More...

void	FLEXIO_I2S_TransferRxCreateHandle (FLEXIO_I2S_Type base, flexio_i2s_handle_t handle, flexio_i2s_callback_t callback, void *userData)
	Initializes the FlexIO I2S receive handle. More...

status_t	FLEXIO_I2S_TransferSendNonBlocking (FLEXIO_I2S_Type base, flexio_i2s_handle_t handle, flexio_i2s_transfer_t *xfer)
	Performs an interrupt non-blocking send transfer on FlexIO I2S. More...

status_t	FLEXIO_I2S_TransferReceiveNonBlocking (FLEXIO_I2S_Type base, flexio_i2s_handle_t handle, flexio_i2s_transfer_t *xfer)
	Performs an interrupt non-blocking receive transfer on FlexIO I2S. More...

void	FLEXIO_I2S_TransferAbortSend (FLEXIO_I2S_Type base, flexio_i2s_handle_t handle)
	Aborts the current send. More...

void	FLEXIO_I2S_TransferAbortReceive (FLEXIO_I2S_Type base, flexio_i2s_handle_t handle)
	Aborts the current receive. More...

status_t	FLEXIO_I2S_TransferGetSendCount (FLEXIO_I2S_Type base, flexio_i2s_handle_t handle, size_t *count)
	Gets the remaining bytes to be sent. More...

status_t	FLEXIO_I2S_TransferGetReceiveCount (FLEXIO_I2S_Type base, flexio_i2s_handle_t handle, size_t *count)
	Gets the remaining bytes to be received. More...

void	FLEXIO_I2S_TransferTxHandleIRQ (void i2sBase, void i2sHandle)
	Tx interrupt handler. More...

void	FLEXIO_I2S_TransferRxHandleIRQ (void i2sBase, void i2sHandle)
	Rx interrupt handler. More...

Data Structure Documentation

struct FLEXIO_I2S_Type

Data Fields
FLEXIO_Type *	flexioBase
	FlexIO base pointer.

uint8_t	txPinIndex
	Tx data pin index in FlexIO pins.

uint8_t	rxPinIndex
	Rx data pin index.

uint8_t	bclkPinIndex
	Bit clock pin index.

uint8_t	fsPinIndex
	Frame sync pin index.

uint8_t	txShifterIndex
	Tx data shifter index.

uint8_t	rxShifterIndex
	Rx data shifter index.

uint8_t	bclkTimerIndex
	Bit clock timer index.

uint8_t	fsTimerIndex
	Frame sync timer index.

struct flexio_i2s_config_t

Data Fields
bool	enableI2S
	Enable FlexIO I2S.

flexio_i2s_master_slave_t	masterSlave
	Master or slave.

flexio_pin_polarity_t	txPinPolarity
	Tx data pin polarity, active high or low.

flexio_pin_polarity_t	rxPinPolarity
	Rx data pin polarity.

flexio_pin_polarity_t	bclkPinPolarity
	Bit clock pin polarity.

flexio_pin_polarity_t	fsPinPolarity
	Frame sync pin polarity.

flexio_shifter_timer_polarity_t	txTimerPolarity
	Tx data valid on bclk rising or falling edge.

flexio_shifter_timer_polarity_t	rxTimerPolarity
	Rx data valid on bclk rising or falling edge.

struct flexio_i2s_format_t

Data Fields
uint8_t	bitWidth
	Bit width of audio data, always 8/16/24/32 bits.

uint32_t	sampleRate_Hz
	Sample rate of the audio data.

struct flexio_i2s_transfer_t

Data Fields
uint8_t *	data
	Data buffer start pointer.

size_t	dataSize
	Bytes to be transferred. More...

Field Documentation

size_t flexio_i2s_transfer_t::dataSize

struct _flexio_i2s_handle

Data Fields
uint32_t	state
	Internal state.

flexio_i2s_callback_t	callback
	Callback function called at transfer event.

void *	userData
	Callback parameter passed to callback function.

uint8_t	bitWidth
	Bit width for transfer, 8/16/24/32bits.

flexio_i2s_transfer_t	queue [FLEXIO_I2S_XFER_QUEUE_SIZE]
	Transfer queue storing queued transfer.

size_t	transferSize [FLEXIO_I2S_XFER_QUEUE_SIZE]
	Data bytes need to transfer.

volatile uint8_t	queueUser
	Index for user to queue transfer.

volatile uint8_t	queueDriver
	Index for driver to get the transfer data and size.

Macro Definition Documentation

#define FSL_FLEXIO_I2S_DRIVER_VERSION (MAKE_VERSION(2, 2, 0))

#define I2S_RETRY_TIMES 0U /* Define to zero means keep waiting until the flag is assert/deassert. */

#define FLEXIO_I2S_XFER_QUEUE_SIZE (4U)

Enumeration Type Documentation

anonymous enum

Enumerator
kStatus_FLEXIO_I2S_Idle	FlexIO I2S is in idle state.
kStatus_FLEXIO_I2S_TxBusy	FlexIO I2S Tx is busy.
kStatus_FLEXIO_I2S_RxBusy	FlexIO I2S Tx is busy.
kStatus_FLEXIO_I2S_Error	FlexIO I2S error occurred.
kStatus_FLEXIO_I2S_QueueFull	FlexIO I2S transfer queue is full.
kStatus_FLEXIO_I2S_Timeout	FlexIO I2S timeout polling status flags.

enum flexio_i2s_master_slave_t

Enumerator
kFLEXIO_I2S_Master	Master mode.
kFLEXIO_I2S_Slave	Slave mode.

anonymous enum

Enumerator
kFLEXIO_I2S_TxDataRegEmptyInterruptEnable	Transmit buffer empty interrupt enable.
kFLEXIO_I2S_RxDataRegFullInterruptEnable	Receive buffer full interrupt enable.

anonymous enum

Enumerator
kFLEXIO_I2S_TxDataRegEmptyFlag	Transmit buffer empty flag.
kFLEXIO_I2S_RxDataRegFullFlag	Receive buffer full flag.

enum flexio_i2s_sample_rate_t

Enumerator
kFLEXIO_I2S_SampleRate8KHz	Sample rate 8000Hz.
kFLEXIO_I2S_SampleRate11025Hz	Sample rate 11025Hz.
kFLEXIO_I2S_SampleRate12KHz	Sample rate 12000Hz.
kFLEXIO_I2S_SampleRate16KHz	Sample rate 16000Hz.
kFLEXIO_I2S_SampleRate22050Hz	Sample rate 22050Hz.
kFLEXIO_I2S_SampleRate24KHz	Sample rate 24000Hz.
kFLEXIO_I2S_SampleRate32KHz	Sample rate 32000Hz.
kFLEXIO_I2S_SampleRate44100Hz	Sample rate 44100Hz.
kFLEXIO_I2S_SampleRate48KHz	Sample rate 48000Hz.
kFLEXIO_I2S_SampleRate96KHz	Sample rate 96000Hz.

enum flexio_i2s_word_width_t

Enumerator
kFLEXIO_I2S_WordWidth8bits	Audio data width 8 bits.
kFLEXIO_I2S_WordWidth16bits	Audio data width 16 bits.
kFLEXIO_I2S_WordWidth24bits	Audio data width 24 bits.
kFLEXIO_I2S_WordWidth32bits	Audio data width 32 bits.

Function Documentation

void FLEXIO_I2S_Init	(	FLEXIO_I2S_Type *	base,
		const flexio_i2s_config_t *	config
	)

This API configures FlexIO pins and shifter to I2S and configures the FlexIO I2S with a configuration structure. The configuration structure can be filled by the user, or be set with default values by FLEXIO_I2S_GetDefaultConfig().

Note: This API should be called at the beginning of the application to use the FlexIO I2S driver. Otherwise, any access to the FlexIO I2S module can cause hard fault because the clock is not enabled.

Parameters

base	FlexIO I2S base pointer
config	FlexIO I2S configure structure.

void FLEXIO_I2S_GetDefaultConfig ( flexio_i2s_config_t * config )

The purpose of this API is to get the configuration structure initialized for use in FLEXIO_I2S_Init(). Users may use the initialized structure unchanged in FLEXIO_I2S_Init() or modify some fields of the structure before calling FLEXIO_I2S_Init().

Parameters

config pointer to master configuration structure

void FLEXIO_I2S_Deinit ( FLEXIO_I2S_Type * base )

Calling this API resets the FlexIO I2S shifter and timer config. After calling this API, call the FLEXO_I2S_Init to use the FlexIO I2S module.

Parameters

base	FlexIO I2S base pointer

static void FLEXIO_I2S_Enable	(	FLEXIO_I2S_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	Pointer to FLEXIO_I2S_Type
enable	True to enable, false dose not have any effect.

uint32_t FLEXIO_I2S_GetStatusFlags ( FLEXIO_I2S_Type * base )

Parameters

base	Pointer to FLEXIO_I2S_Type structure

Returns: Status flag, which are ORed by the enumerators in the _flexio_i2s_status_flags.

void FLEXIO_I2S_EnableInterrupts	(	FLEXIO_I2S_Type *	base,
		uint32_t	mask
	)

This function enables the FlexIO UART interrupt.

Parameters

base	Pointer to FLEXIO_I2S_Type structure
mask	interrupt source

void FLEXIO_I2S_DisableInterrupts	(	FLEXIO_I2S_Type *	base,
		uint32_t	mask
	)

This function enables the FlexIO UART interrupt.

Parameters

base	pointer to FLEXIO_I2S_Type structure
mask	interrupt source

static void FLEXIO_I2S_TxEnableDMA	(	FLEXIO_I2S_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	FlexIO I2S base pointer
enable	True means enable DMA, false means disable DMA.

static void FLEXIO_I2S_RxEnableDMA	(	FLEXIO_I2S_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	FlexIO I2S base pointer
enable	True means enable DMA, false means disable DMA.

static uint32_t FLEXIO_I2S_TxGetDataRegisterAddress ( FLEXIO_I2S_Type * base )

inlinestatic

This function returns the I2S data register address, mainly used by DMA/eDMA.

Parameters

base	Pointer to FLEXIO_I2S_Type structure

Returns: FlexIO i2s send data register address.

static uint32_t FLEXIO_I2S_RxGetDataRegisterAddress ( FLEXIO_I2S_Type * base )

inlinestatic

This function returns the I2S data register address, mainly used by DMA/eDMA.

Parameters

base	Pointer to FLEXIO_I2S_Type structure

Returns: FlexIO i2s receive data register address.

void FLEXIO_I2S_MasterSetFormat	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_format_t *	format,
		uint32_t	srcClock_Hz
	)

Audio format can be changed in run-time of FlexIO I2S. This function configures the sample rate and audio data format to be transferred.

Parameters

base	Pointer to FLEXIO_I2S_Type structure
format	Pointer to FlexIO I2S audio data format structure.
srcClock_Hz	I2S master clock source frequency in Hz.

void FLEXIO_I2S_SlaveSetFormat	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_format_t *	format
	)

Audio format can be changed in run-time of FlexIO I2S. This function configures the sample rate and audio data format to be transferred.

Parameters

base	Pointer to FLEXIO_I2S_Type structure
format	Pointer to FlexIO I2S audio data format structure.

status_t FLEXIO_I2S_WriteBlocking	(	FLEXIO_I2S_Type *	base,
		uint8_t	bitWidth,
		uint8_t *	txData,
		size_t	size
	)

Note: This function blocks via polling until data is ready to be sent.

Parameters

base	FlexIO I2S base pointer.
bitWidth	How many bits in a audio word, usually 8/16/24/32 bits.
txData	Pointer to the data to be written.
size	Bytes to be written.

Return values

kStatus_Success	Successfully write data.
kStatus_FLEXIO_I2C_Timeout	Timeout polling status flags.

static void FLEXIO_I2S_WriteData	(	FLEXIO_I2S_Type *	base,
		uint8_t	bitWidth,
		uint32_t	data
	)

inlinestatic

Parameters

base	FlexIO I2S base pointer.
bitWidth	How many bits in a audio word, usually 8/16/24/32 bits.
data	Data to be written.

status_t FLEXIO_I2S_ReadBlocking	(	FLEXIO_I2S_Type *	base,
		uint8_t	bitWidth,
		uint8_t *	rxData,
		size_t	size
	)

Note: This function blocks via polling until data is ready to be sent.

Parameters

base	FlexIO I2S base pointer
bitWidth	How many bits in a audio word, usually 8/16/24/32 bits.
rxData	Pointer to the data to be read.
size	Bytes to be read.

Return values

kStatus_Success	Successfully read data.
kStatus_FLEXIO_I2C_Timeout	Timeout polling status flags.

static uint32_t FLEXIO_I2S_ReadData ( FLEXIO_I2S_Type * base )

inlinestatic

Parameters

base	FlexIO I2S base pointer

Returns: Data read from data register.

void FLEXIO_I2S_TransferTxCreateHandle	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_handle_t *	handle,
		flexio_i2s_callback_t	callback,
		void *	userData
	)

This function initializes the FlexIO I2S handle which can be used for other FlexIO I2S transactional APIs. Call this API once to get the initialized handle.

Parameters

base	Pointer to FLEXIO_I2S_Type structure
handle	Pointer to flexio_i2s_handle_t structure to store the transfer state.
callback	FlexIO I2S callback function, which is called while finished a block.
userData	User parameter for the FlexIO I2S callback.

void FLEXIO_I2S_TransferSetFormat	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_handle_t *	handle,
		flexio_i2s_format_t *	format,
		uint32_t	srcClock_Hz
	)

Audio format can be changed at run-time of FlexIO I2S. This function configures the sample rate and audio data format to be transferred.

Parameters

base	Pointer to FLEXIO_I2S_Type structure.
handle	FlexIO I2S handle pointer.
format	Pointer to audio data format structure.
srcClock_Hz	FlexIO I2S bit clock source frequency in Hz. This parameter should be 0 while in slave mode.

void FLEXIO_I2S_TransferRxCreateHandle	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_handle_t *	handle,
		flexio_i2s_callback_t	callback,
		void *	userData
	)

This function initializes the FlexIO I2S handle which can be used for other FlexIO I2S transactional APIs. Call this API once to get the initialized handle.

Parameters

base	Pointer to FLEXIO_I2S_Type structure.
handle	Pointer to flexio_i2s_handle_t structure to store the transfer state.
callback	FlexIO I2S callback function, which is called while finished a block.
userData	User parameter for the FlexIO I2S callback.

status_t FLEXIO_I2S_TransferSendNonBlocking	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_handle_t *	handle,
		flexio_i2s_transfer_t *	xfer
	)

Note: The API returns immediately after transfer initiates. Call FLEXIO_I2S_GetRemainingBytes to poll the transfer status and check whether the transfer is finished. If the return status is 0, the transfer is finished.

Parameters

base	Pointer to FLEXIO_I2S_Type structure.
handle	Pointer to flexio_i2s_handle_t structure which stores the transfer state
xfer	Pointer to flexio_i2s_transfer_t structure

Return values

kStatus_Success	Successfully start the data transmission.
kStatus_FLEXIO_I2S_TxBusy	Previous transmission still not finished, data not all written to TX register yet.
kStatus_InvalidArgument	The input parameter is invalid.

status_t FLEXIO_I2S_TransferReceiveNonBlocking	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_handle_t *	handle,
		flexio_i2s_transfer_t *	xfer
	)

Note: The API returns immediately after transfer initiates. Call FLEXIO_I2S_GetRemainingBytes to poll the transfer status to check whether the transfer is finished. If the return status is 0, the transfer is finished.

Parameters

base	Pointer to FLEXIO_I2S_Type structure.
handle	Pointer to flexio_i2s_handle_t structure which stores the transfer state
xfer	Pointer to flexio_i2s_transfer_t structure

Return values

kStatus_Success	Successfully start the data receive.
kStatus_FLEXIO_I2S_RxBusy	Previous receive still not finished.
kStatus_InvalidArgument	The input parameter is invalid.

void FLEXIO_I2S_TransferAbortSend	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_handle_t *	handle
	)

Note: This API can be called at any time when interrupt non-blocking transfer initiates to abort the transfer in a early time.

Parameters

base	Pointer to FLEXIO_I2S_Type structure.
handle	Pointer to flexio_i2s_handle_t structure which stores the transfer state

void FLEXIO_I2S_TransferAbortReceive	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_handle_t *	handle
	)

Note: This API can be called at any time when interrupt non-blocking transfer initiates to abort the transfer in a early time.

Parameters

base	Pointer to FLEXIO_I2S_Type structure.
handle	Pointer to flexio_i2s_handle_t structure which stores the transfer state

status_t FLEXIO_I2S_TransferGetSendCount	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_handle_t *	handle,
		size_t *	count
	)

Parameters

base	Pointer to FLEXIO_I2S_Type structure.
handle	Pointer to flexio_i2s_handle_t structure which stores the transfer state
count	Bytes sent.

Return values

kStatus_Success	Succeed get the transfer count.
kStatus_NoTransferInProgress	There is not a non-blocking transaction currently in progress.

status_t FLEXIO_I2S_TransferGetReceiveCount	(	FLEXIO_I2S_Type *	base,
		flexio_i2s_handle_t *	handle,
		size_t *	count
	)

Parameters

base	Pointer to FLEXIO_I2S_Type structure.
handle	Pointer to flexio_i2s_handle_t structure which stores the transfer state
count	Bytes recieved.

Returns: count Bytes received.

Return values

kStatus_Success	Succeed get the transfer count.
kStatus_NoTransferInProgress	There is not a non-blocking transaction currently in progress.

void FLEXIO_I2S_TransferTxHandleIRQ	(	void *	i2sBase,
		void *	i2sHandle
	)

Parameters

i2sBase	Pointer to FLEXIO_I2S_Type structure.
i2sHandle	Pointer to flexio_i2s_handle_t structure

void FLEXIO_I2S_TransferRxHandleIRQ	(	void *	i2sBase,
		void *	i2sHandle
	)

Parameters

i2sBase	Pointer to FLEXIO_I2S_Type structure.
i2sHandle	Pointer to flexio_i2s_handle_t structure.

Overview

Typical use case

FlexIO I2S send/receive using an interrupt method

FLEXIO_I2S send/receive using a DMA method

Data Structures

Macros

Typedefs

Enumerations

Driver version

Initialization and deinitialization

Status

Interrupts

DMA Control

Bus Operations

Transactional

Data Structure Documentation

Data Fields

Data Fields

Data Fields

Data Fields

Field Documentation

Data Fields

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation