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 (4)
	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	_i2s_status { kStatus_I2S_BufferComplete, kStatus_I2S_Done = MAKE_STATUS(kStatusGroup_I2S, 1), kStatus_I2S_Busy }
	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...

Driver version
#define	FSL_I2S_DRIVER_VERSION (MAKE_VERSION(2, 0, 0))
	I2S driver version 2.0.0. 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...

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...

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
volatile uint8_t *	data
	Pointer to data buffer. More...

volatile size_t	dataSize
	Buffer size in bytes. More...

Field Documentation

volatile uint8_t* i2s_transfer_t::data

volatile 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)

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.

volatile uint8_t	watermark
	FIFO trigger level.

Macro Definition Documentation

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

Current version: 2.0.0

Change log:

Version 2.0.0
- initial version

#define I2S_NUM_BUFFERS (4)

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

enum _i2s_status

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.

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_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.

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