Overview

Files
file	fsl_i2s.h

Data Structures
struct	i2s_config_t
	I2S configuration structure. More...

struct	i2s_transfer_t
	Buffer to transfer from or receive audio data into. More...

struct	i2s_handle_t
	Members not to be accessed / modified outside of the driver. More...

Macros
#define	I2S_NUM_BUFFERS (4U)
	Number of buffers . More...

Typedefs
typedef void(*	i2s_transfer_callback_t )(I2S_Type base, i2s_handle_t handle, status_t completionStatus, void *userData)
	Callback function invoked from transactional API on completion of a single buffer transfer. More...

Enumerations
enum	{ kStatus_I2S_BufferComplete, kStatus_I2S_Done = MAKE_STATUS(kStatusGroup_I2S, 1), kStatus_I2S_Busy }
	_i2s_status I2S status codes. More...

enum	i2s_flags_t { kI2S_TxErrorFlag = I2S_FIFOINTENSET_TXERR_MASK, kI2S_TxLevelFlag = I2S_FIFOINTENSET_TXLVL_MASK, kI2S_RxErrorFlag = I2S_FIFOINTENSET_RXERR_MASK, kI2S_RxLevelFlag = I2S_FIFOINTENSET_RXLVL_MASK }
	I2S flags. More...

enum	i2s_master_slave_t { kI2S_MasterSlaveNormalSlave = 0x0, kI2S_MasterSlaveWsSyncMaster = 0x1, kI2S_MasterSlaveExtSckMaster = 0x2, kI2S_MasterSlaveNormalMaster = 0x3 }
	Master / slave mode. More...

enum	i2s_mode_t { kI2S_ModeI2sClassic = 0x0, kI2S_ModeDspWs50 = 0x1, kI2S_ModeDspWsShort = 0x2, kI2S_ModeDspWsLong = 0x3 }
	I2S mode. More...

enum	{ kI2S_SecondaryChannel1 = 0U, kI2S_SecondaryChannel2 = 1U, kI2S_SecondaryChannel3 = 2U }
	_i2s_secondary_channel I2S secondary channel. More...

Driver version
#define	FSL_I2S_DRIVER_VERSION (MAKE_VERSION(2, 2, 0))
	I2S driver version 2.2.0. More...

Initialization and deinitialization
void	I2S_TxInit (I2S_Type base, const i2s_config_t config)
	Initializes the FLEXCOMM peripheral for I2S transmit functionality. More...

void	I2S_RxInit (I2S_Type base, const i2s_config_t config)
	Initializes the FLEXCOMM peripheral for I2S receive functionality. More...

void	I2S_TxGetDefaultConfig (i2s_config_t *config)
	Sets the I2S Tx configuration structure to default values. More...

void	I2S_RxGetDefaultConfig (i2s_config_t *config)
	Sets the I2S Rx configuration structure to default values. More...

void	I2S_Deinit (I2S_Type *base)
	De-initializes the I2S peripheral. More...

void	I2S_SetBitClockRate (I2S_Type *base, uint32_t sourceClockHz, uint32_t sampleRate, uint32_t bitWidth, uint32_t channelNumbers)
	Transmitter/Receiver bit clock rate configurations. More...

Non-blocking API
void	I2S_TxTransferCreateHandle (I2S_Type base, i2s_handle_t handle, i2s_transfer_callback_t callback, void *userData)
	Initializes handle for transfer of audio data. More...

status_t	I2S_TxTransferNonBlocking (I2S_Type base, i2s_handle_t handle, i2s_transfer_t transfer)
	Begins or queue sending of the given data. More...

void	I2S_TxTransferAbort (I2S_Type base, i2s_handle_t handle)
	Aborts sending of data. More...

void	I2S_RxTransferCreateHandle (I2S_Type base, i2s_handle_t handle, i2s_transfer_callback_t callback, void *userData)
	Initializes handle for reception of audio data. More...

status_t	I2S_RxTransferNonBlocking (I2S_Type base, i2s_handle_t handle, i2s_transfer_t transfer)
	Begins or queue reception of data into given buffer. More...

void	I2S_RxTransferAbort (I2S_Type base, i2s_handle_t handle)
	Aborts receiving of data. More...

status_t	I2S_TransferGetCount (I2S_Type base, i2s_handle_t handle, size_t *count)
	Returns number of bytes transferred so far. More...

status_t	I2S_TransferGetErrorCount (I2S_Type base, i2s_handle_t handle, size_t *count)
	Returns number of buffer underruns or overruns. More...

Enable / disable
static void	I2S_Enable (I2S_Type *base)
	Enables I2S operation. More...

void	I2S_EnableSecondaryChannel (I2S_Type *base, uint32_t channel, bool oneChannel, uint32_t position)
	Enables I2S secondary channel. More...

static void	I2S_DisableSecondaryChannel (I2S_Type *base, uint32_t channel)
	Disables I2S secondary channel. More...

static void	I2S_Disable (I2S_Type *base)
	Disables I2S operation. More...

Interrupts
static void	I2S_EnableInterrupts (I2S_Type *base, uint32_t interruptMask)
	Enables I2S FIFO interrupts. More...

static void	I2S_DisableInterrupts (I2S_Type *base, uint32_t interruptMask)
	Disables I2S FIFO interrupts. More...

static uint32_t	I2S_GetEnabledInterrupts (I2S_Type *base)
	Returns the set of currently enabled I2S FIFO interrupts. More...

void	I2S_TxHandleIRQ (I2S_Type base, i2s_handle_t handle)
	Invoked from interrupt handler when transmit FIFO level decreases. More...

void	I2S_RxHandleIRQ (I2S_Type base, i2s_handle_t handle)
	Invoked from interrupt handler when receive FIFO level decreases. More...

Data Structure Documentation

struct i2s_config_t

Data Fields
i2s_master_slave_t	masterSlave
	Master / slave configuration.

i2s_mode_t	mode
	I2S mode.

bool	rightLow
	Right channel data in low portion of FIFO.

bool	leftJust
	Left justify data in FIFO.

bool	pdmData
	Data source is the D-Mic subsystem.

bool	sckPol
	SCK polarity.

bool	wsPol
	WS polarity.

uint16_t	divider
	Flexcomm function clock divider (1 - 4096)

bool	oneChannel
	true mono, false stereo

uint8_t	dataLength
	Data length (4 - 32)

uint16_t	frameLength
	Frame width (4 - 512)

uint16_t	position
	Data position in the frame.

uint8_t	watermark
	FIFO trigger level.

bool	txEmptyZero
	Transmit zero when buffer becomes empty or last item.

bool	pack48
	Packing format for 48-bit data (false - 24 bit values, true - alternating 32-bit and 16-bit values)

struct i2s_transfer_t

Data Fields
uint8_t *	data
	Pointer to data buffer. More...

size_t	dataSize
	Buffer size in bytes. More...

Field Documentation

uint8_t* i2s_transfer_t::data

size_t i2s_transfer_t::dataSize

struct _i2s_handle

Transactional state of the intialized transfer or receive I2S operation.

Data Fields
uint32_t	state
	State of transfer.

i2s_transfer_callback_t	completionCallback
	Callback function pointer.

void *	userData
	Application data passed to callback.

bool	oneChannel
	true mono, false stereo

uint8_t	dataLength
	Data length (4 - 32)

bool	pack48
	Packing format for 48-bit data (false - 24 bit values, true - alternating 32-bit and 16-bit values)

uint8_t	watermark
	FIFO trigger level.

bool	useFifo48H
	When dataLength 17-24: true use FIFOWR48H, false use FIFOWR.

volatile i2s_transfer_t	i2sQueue [I2S_NUM_BUFFERS]
	Transfer queue storing transfer buffers.

volatile uint8_t	queueUser
	Queue index where user's next transfer will be stored.

volatile uint8_t	queueDriver
	Queue index of buffer actually used by the driver.

volatile uint32_t	errorCount
	Number of buffer underruns/overruns.

volatile uint32_t	transferCount
	Number of bytes transferred.

Macro Definition Documentation

#define FSL_I2S_DRIVER_VERSION (MAKE_VERSION(2, 2, 0))

#define I2S_NUM_BUFFERS (4U)

Typedef Documentation

typedef void(* i2s_transfer_callback_t)(I2S_Type *base, i2s_handle_t *handle, status_t completionStatus, void *userData)

Parameters

base	I2S base pointer.
handle	pointer to I2S transaction.
completionStatus	status of the transaction.
userData	optional pointer to user arguments data.

Enumeration Type Documentation

anonymous enum

Enumerator
kStatus_I2S_BufferComplete	Transfer from/into a single buffer has completed.
kStatus_I2S_Done	All buffers transfers have completed.
kStatus_I2S_Busy	Already performing a transfer and cannot queue another buffer.

enum i2s_flags_t

Note: These enums are meant to be OR'd together to form a bit mask.

Enumerator
kI2S_TxErrorFlag	TX error interrupt.
kI2S_TxLevelFlag	TX level interrupt.
kI2S_RxErrorFlag	RX error interrupt.
kI2S_RxLevelFlag	RX level interrupt.

enum i2s_master_slave_t

Enumerator
kI2S_MasterSlaveNormalSlave	Normal slave.
kI2S_MasterSlaveWsSyncMaster	WS synchronized master.
kI2S_MasterSlaveExtSckMaster	Master using existing SCK.
kI2S_MasterSlaveNormalMaster	Normal master.

enum i2s_mode_t

Enumerator
kI2S_ModeI2sClassic	I2S classic mode.
kI2S_ModeDspWs50	DSP mode, WS having 50% duty cycle.
kI2S_ModeDspWsShort	DSP mode, WS having one clock long pulse.
kI2S_ModeDspWsLong	DSP mode, WS having one data slot long pulse.

anonymous enum

Enumerator
kI2S_SecondaryChannel1	secondary channel 1
kI2S_SecondaryChannel2	secondary channel 2
kI2S_SecondaryChannel3	secondary channel 3

Function Documentation

void I2S_TxInit	(	I2S_Type *	base,
		const i2s_config_t *	config
	)

Ungates the FLEXCOMM clock and configures the module for I2S transmission using a configuration structure. The configuration structure can be custom filled or set with default values by I2S_TxGetDefaultConfig().

Note: This API should be called at the beginning of the application to use the I2S driver.

Parameters

base	I2S base pointer.
config	pointer to I2S configuration structure.

void I2S_RxInit	(	I2S_Type *	base,
		const i2s_config_t *	config
	)

Ungates the FLEXCOMM clock and configures the module for I2S receive using a configuration structure. The configuration structure can be custom filled or set with default values by I2S_RxGetDefaultConfig().

Note: This API should be called at the beginning of the application to use the I2S driver.

Parameters

base	I2S base pointer.
config	pointer to I2S configuration structure.

void I2S_TxGetDefaultConfig ( i2s_config_t * config )

This API initializes the configuration structure for use in I2S_TxInit(). The initialized structure can remain unchanged in I2S_TxInit(), or it can be modified before calling I2S_TxInit(). Example:

i2s_config_t config;

I2S_TxGetDefaultConfig(&config);

Default values:

*   config->masterSlave = kI2S_MasterSlaveNormalMaster;
*   config->mode = kI2S_ModeI2sClassic;
*   config->rightLow = false;
*   config->leftJust = false;
*   config->pdmData = false;
*   config->sckPol = false;
*   config->wsPol = false;
*   config->divider = 1;
*   config->oneChannel = false;
*   config->dataLength = 16;
*   config->frameLength = 32;
*   config->position = 0;
*   config->watermark = 4;
*   config->txEmptyZero = true;
*   config->pack48 = false;
* 

Parameters

config pointer to I2S configuration structure.

void I2S_RxGetDefaultConfig ( i2s_config_t * config )

This API initializes the configuration structure for use in I2S_RxInit(). The initialized structure can remain unchanged in I2S_RxInit(), or it can be modified before calling I2S_RxInit(). Example:

i2s_config_t config;

I2S_RxGetDefaultConfig(&config);

Default values:

*   config->masterSlave = kI2S_MasterSlaveNormalSlave;
*   config->mode = kI2S_ModeI2sClassic;
*   config->rightLow = false;
*   config->leftJust = false;
*   config->pdmData = false;
*   config->sckPol = false;
*   config->wsPol = false;
*   config->divider = 1;
*   config->oneChannel = false;
*   config->dataLength = 16;
*   config->frameLength = 32;
*   config->position = 0;
*   config->watermark = 4;
*   config->txEmptyZero = false;
*   config->pack48 = false;
* 

Parameters

config pointer to I2S configuration structure.

void I2S_Deinit ( I2S_Type * base )

This API gates the FLEXCOMM clock. The I2S module can't operate unless I2S_TxInit or I2S_RxInit is called to enable the clock.

Parameters

base	I2S base pointer.

void I2S_SetBitClockRate	(	I2S_Type *	base,
		uint32_t	sourceClockHz,
		uint32_t	sampleRate,
		uint32_t	bitWidth,
		uint32_t	channelNumbers
	)

Parameters

base	SAI base pointer.
sourceClockHz,bit	clock source frequency.
sampleRate	audio data sample rate.
bitWidth,audio	data bitWidth.
channelNumbers,audio	channel numbers.

void I2S_TxTransferCreateHandle	(	I2S_Type *	base,
		i2s_handle_t *	handle,
		i2s_transfer_callback_t	callback,
		void *	userData
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.
callback	function to be called back when transfer is done or fails.
userData	pointer to data passed to callback.

status_t I2S_TxTransferNonBlocking	(	I2S_Type *	base,
		i2s_handle_t *	handle,
		i2s_transfer_t	transfer
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.
transfer	data buffer.

Return values

kStatus_Success
kStatus_I2S_Busy	if all queue slots are occupied with unsent buffers.

void I2S_TxTransferAbort	(	I2S_Type *	base,
		i2s_handle_t *	handle
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.

void I2S_RxTransferCreateHandle	(	I2S_Type *	base,
		i2s_handle_t *	handle,
		i2s_transfer_callback_t	callback,
		void *	userData
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.
callback	function to be called back when transfer is done or fails.
userData	pointer to data passed to callback.

status_t I2S_RxTransferNonBlocking	(	I2S_Type *	base,
		i2s_handle_t *	handle,
		i2s_transfer_t	transfer
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.
transfer	data buffer.

Return values

kStatus_Success
kStatus_I2S_Busy	if all queue slots are occupied with buffers which are not full.

void I2S_RxTransferAbort	(	I2S_Type *	base,
		i2s_handle_t *	handle
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.

status_t I2S_TransferGetCount	(	I2S_Type *	base,
		i2s_handle_t *	handle,
		size_t *	count
	)

Parameters

	base	I2S base pointer.
	handle	pointer to handle structure.
[out]	count	number of bytes transferred so far by the non-blocking transaction.

Return values

kStatus_Success
kStatus_NoTransferInProgress	there is no non-blocking transaction currently in progress.

status_t I2S_TransferGetErrorCount	(	I2S_Type *	base,
		i2s_handle_t *	handle,
		size_t *	count
	)

Parameters

	base	I2S base pointer.
	handle	pointer to handle structure.
[out]	count	number of transmit errors encountered so far by the non-blocking transaction.

Return values

kStatus_Success
kStatus_NoTransferInProgress	there is no non-blocking transaction currently in progress.

static void I2S_Enable ( I2S_Type * base )

inlinestatic

Parameters

base	I2S base pointer.

void I2S_EnableSecondaryChannel	(	I2S_Type *	base,
		uint32_t	channel,
		bool	oneChannel,
		uint32_t	position
	)

Parameters

base	I2S base pointer.
channel	seondary channel channel number, reference _i2s_secondary_channel.
oneChannel	true is treated as single channel, functionality left channel for this pair.
position	define the location within the frame of the data, should not bigger than 0x1FFU.

static void I2S_DisableSecondaryChannel	(	I2S_Type *	base,
		uint32_t	channel
	)

inlinestatic

Parameters

base	I2S base pointer.
channel	seondary channel channel number, reference _i2s_secondary_channel.

static void I2S_Disable ( I2S_Type * base )

inlinestatic

Parameters

base	I2S base pointer.

static void I2S_EnableInterrupts	(	I2S_Type *	base,
		uint32_t	interruptMask
	)

inlinestatic

Parameters

base	I2S base pointer.
interruptMask	bit mask of interrupts to enable. See i2s_flags_t for the set of constants that should be OR'd together to form the bit mask.

static void I2S_DisableInterrupts	(	I2S_Type *	base,
		uint32_t	interruptMask
	)

inlinestatic

Parameters

base	I2S base pointer.
interruptMask	bit mask of interrupts to enable. See i2s_flags_t for the set of constants that should be OR'd together to form the bit mask.

static uint32_t I2S_GetEnabledInterrupts ( I2S_Type * base )

inlinestatic

Parameters

base	I2S base pointer.

Returns: A bitmask composed of i2s_flags_t enumerators OR'd together to indicate the set of enabled interrupts.

void I2S_TxHandleIRQ	(	I2S_Type *	base,
		i2s_handle_t *	handle
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.

void I2S_RxHandleIRQ	(	I2S_Type *	base,
		i2s_handle_t *	handle
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.

Overview

Files

Data Structures

Macros

Typedefs

Enumerations

Driver version

Initialization and deinitialization

Non-blocking API

Enable / disable

Interrupts

Data Structure Documentation

Data Fields

Data Fields

Field Documentation

Data Fields

Macro Definition Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation