MCUXpresso SDK API Reference Manual  Rev. 0
NXP Semiconductors
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Data Structures

struct  i2c_master_config_t
 Structure with settings to initialize the I2C master module. More...
 
struct  i2c_master_transfer_t
 Non-blocking transfer descriptor structure. More...
 
struct  i2c_master_handle_t
 Driver handle for master non-blocking APIs. More...
 

Typedefs

typedef void(* i2c_master_transfer_callback_t )(I2C_Type *base, i2c_master_handle_t *handle, status_t completionStatus, void *userData)
 Master completion callback function pointer type. More...
 

Enumerations

enum  _i2c_master_flags {
  kI2C_MasterPendingFlag = I2C_STAT_MSTPENDING_MASK,
  kI2C_MasterArbitrationLostFlag,
  kI2C_MasterStartStopErrorFlag
}
 I2C master peripheral flags. More...
 
enum  i2c_direction_t {
  kI2C_Write = 0U,
  kI2C_Read = 1U
}
 Direction of master and slave transfers. More...
 
enum  _i2c_master_transfer_flags {
  kI2C_TransferDefaultFlag = 0x00U,
  kI2C_TransferNoStartFlag = 0x01U,
  kI2C_TransferRepeatedStartFlag = 0x02U,
  kI2C_TransferNoStopFlag = 0x04U
}
 Transfer option flags. More...
 
enum  _i2c_transfer_states
 States for the state machine used by transactional APIs. More...
 

Initialization and deinitialization

void I2C_MasterGetDefaultConfig (i2c_master_config_t *masterConfig)
 Provides a default configuration for the I2C master peripheral. More...
 
void I2C_MasterInit (I2C_Type *base, const i2c_master_config_t *masterConfig, uint32_t srcClock_Hz)
 Initializes the I2C master peripheral. More...
 
void I2C_MasterDeinit (I2C_Type *base)
 Deinitializes the I2C master peripheral. More...
 
uint32_t I2C_GetInstance (I2C_Type *base)
 Returns an instance number given a base address. More...
 
static void I2C_MasterReset (I2C_Type *base)
 Performs a software reset. More...
 
static void I2C_MasterEnable (I2C_Type *base, bool enable)
 Enables or disables the I2C module as master. More...
 

Status

static uint32_t I2C_GetStatusFlags (I2C_Type *base)
 Gets the I2C status flags. More...
 
static void I2C_MasterClearStatusFlags (I2C_Type *base, uint32_t statusMask)
 Clears the I2C master status flag state. More...
 

Interrupts

static void I2C_EnableInterrupts (I2C_Type *base, uint32_t interruptMask)
 Enables the I2C master interrupt requests. More...
 
static void I2C_DisableInterrupts (I2C_Type *base, uint32_t interruptMask)
 Disables the I2C master interrupt requests. More...
 
static uint32_t I2C_GetEnabledInterrupts (I2C_Type *base)
 Returns the set of currently enabled I2C master interrupt requests. More...
 

Bus operations

void I2C_MasterSetBaudRate (I2C_Type *base, uint32_t baudRate_Bps, uint32_t srcClock_Hz)
 Sets the I2C bus frequency for master transactions. More...
 
static bool I2C_MasterGetBusIdleState (I2C_Type *base)
 Returns whether the bus is idle. More...
 
status_t I2C_MasterStart (I2C_Type *base, uint8_t address, i2c_direction_t direction)
 Sends a START on the I2C bus. More...
 
status_t I2C_MasterStop (I2C_Type *base)
 Sends a STOP signal on the I2C bus. More...
 
static status_t I2C_MasterRepeatedStart (I2C_Type *base, uint8_t address, i2c_direction_t direction)
 Sends a REPEATED START on the I2C bus. More...
 
status_t I2C_MasterWriteBlocking (I2C_Type *base, const void *txBuff, size_t txSize, uint32_t flags)
 Performs a polling send transfer on the I2C bus. More...
 
status_t I2C_MasterReadBlocking (I2C_Type *base, void *rxBuff, size_t rxSize, uint32_t flags)
 Performs a polling receive transfer on the I2C bus. More...
 
status_t I2C_MasterTransferBlocking (I2C_Type *base, i2c_master_transfer_t *xfer)
 Performs a master polling transfer on the I2C bus. More...
 

Non-blocking

void I2C_MasterTransferCreateHandle (I2C_Type *base, i2c_master_handle_t *handle, i2c_master_transfer_callback_t callback, void *userData)
 Creates a new handle for the I2C master non-blocking APIs. More...
 
status_t I2C_MasterTransferNonBlocking (I2C_Type *base, i2c_master_handle_t *handle, i2c_master_transfer_t *xfer)
 Performs a non-blocking transaction on the I2C bus. More...
 
status_t I2C_MasterTransferGetCount (I2C_Type *base, i2c_master_handle_t *handle, size_t *count)
 Returns number of bytes transferred so far. More...
 
status_t I2C_MasterTransferAbort (I2C_Type *base, i2c_master_handle_t *handle)
 Terminates a non-blocking I2C master transmission early. More...
 

IRQ handler

void I2C_MasterTransferHandleIRQ (I2C_Type *base, i2c_master_handle_t *handle)
 Reusable routine to handle master interrupts. More...
 

Detailed Description


Data Structure Documentation

struct i2c_master_config_t

This structure holds configuration settings for the I2C peripheral. To initialize this structure to reasonable defaults, call the I2C_MasterGetDefaultConfig() function and pass a pointer to your configuration structure instance.

The configuration structure can be made constant so it resides in flash.

Data Fields

bool enableMaster
 Whether to enable master mode. More...
 
uint32_t baudRate_Bps
 Desired baud rate in bits per second. More...
 
bool enableTimeout
 Enable internal timeout function. More...
 

Field Documentation

bool i2c_master_config_t::enableMaster
uint32_t i2c_master_config_t::baudRate_Bps
bool i2c_master_config_t::enableTimeout
struct _i2c_master_transfer

I2C master transfer typedef.

This structure is used to pass transaction parameters to the I2C_MasterTransferNonBlocking() API.

Data Fields

uint32_t flags
 Bit mask of options for the transfer. More...
 
uint8_t slaveAddress
 The 7-bit slave address. More...
 
i2c_direction_t direction
 Either kI2C_Read or kI2C_Write. More...
 
uint32_t subaddress
 Sub address. More...
 
size_t subaddressSize
 Length of sub address to send in bytes. More...
 
void * data
 Pointer to data to transfer. More...
 
size_t dataSize
 Number of bytes to transfer. More...
 

Field Documentation

uint32_t i2c_master_transfer_t::flags

See enumeration _i2c_master_transfer_flags for available options. Set to 0 or kI2C_TransferDefaultFlag for normal transfers.

uint8_t i2c_master_transfer_t::slaveAddress
i2c_direction_t i2c_master_transfer_t::direction
uint32_t i2c_master_transfer_t::subaddress

Transferred MSB first.

size_t i2c_master_transfer_t::subaddressSize

Maximum size is 4 bytes.

void* i2c_master_transfer_t::data
size_t i2c_master_transfer_t::dataSize
struct _i2c_master_handle

I2C master handle typedef.

Note
The contents of this structure are private and subject to change.

Data Fields

uint8_t state
 Transfer state machine current state. More...
 
uint32_t transferCount
 Indicates progress of the transfer.
 
uint32_t remainingBytes
 Remaining byte count in current state. More...
 
uint8_t * buf
 Buffer pointer for current state. More...
 
i2c_master_transfer_t transfer
 Copy of the current transfer info. More...
 
i2c_master_transfer_callback_t completionCallback
 Callback function pointer. More...
 
void * userData
 Application data passed to callback. More...
 

Field Documentation

uint8_t i2c_master_handle_t::state
uint32_t i2c_master_handle_t::remainingBytes
uint8_t* i2c_master_handle_t::buf
i2c_master_transfer_t i2c_master_handle_t::transfer
i2c_master_transfer_callback_t i2c_master_handle_t::completionCallback
void* i2c_master_handle_t::userData

Typedef Documentation

typedef void(* i2c_master_transfer_callback_t)(I2C_Type *base, i2c_master_handle_t *handle, status_t completionStatus, void *userData)

This callback is used only for the non-blocking master transfer API. Specify the callback you wish to use in the call to I2C_MasterTransferCreateHandle().

Parameters
baseThe I2C peripheral base address.
completionStatusEither kStatus_Success or an error code describing how the transfer completed.
userDataArbitrary pointer-sized value passed from the application.

Enumeration Type Documentation

Note
These enums are meant to be OR'd together to form a bit mask.
Enumerator
kI2C_MasterPendingFlag 

The I2C module is waiting for software interaction.

kI2C_MasterArbitrationLostFlag 

The arbitration of the bus was lost.

There was collision on the bus

kI2C_MasterStartStopErrorFlag 

There was an error during start or stop phase of the transaction.

Enumerator
kI2C_Write 

Master transmit.

kI2C_Read 

Master receive.

Note
These enumerations are intended to be OR'd together to form a bit mask of options for the _i2c_master_transfer::flags field.
Enumerator
kI2C_TransferDefaultFlag 

Transfer starts with a start signal, stops with a stop signal.

kI2C_TransferNoStartFlag 

Don't send a start condition, address, and sub address.

kI2C_TransferRepeatedStartFlag 

Send a repeated start condition.

kI2C_TransferNoStopFlag 

Don't send a stop condition.

Function Documentation

void I2C_MasterGetDefaultConfig ( i2c_master_config_t masterConfig)

This function provides the following default configuration for the I2C master peripheral:

* masterConfig->enableMaster = true;
* masterConfig->baudRate_Bps = 100000U;
* masterConfig->enableTimeout = false;
*

After calling this function, you can override any settings in order to customize the configuration, prior to initializing the master driver with I2C_MasterInit().

Parameters
[out]masterConfigUser provided configuration structure for default values. Refer to i2c_master_config_t.
void I2C_MasterInit ( I2C_Type *  base,
const i2c_master_config_t masterConfig,
uint32_t  srcClock_Hz 
)

This function enables the peripheral clock and initializes the I2C master peripheral as described by the user provided configuration. A software reset is performed prior to configuration.

Parameters
baseThe I2C peripheral base address.
masterConfigUser provided peripheral configuration. Use I2C_MasterGetDefaultConfig() to get a set of defaults that you can override.
srcClock_HzFrequency in Hertz of the I2C functional clock. Used to calculate the baud rate divisors, filter widths, and timeout periods.
void I2C_MasterDeinit ( I2C_Type *  base)

This function disables the I2C master peripheral and gates the clock. It also performs a software reset to restore the peripheral to reset conditions.

Parameters
baseThe I2C peripheral base address.
uint32_t I2C_GetInstance ( I2C_Type *  base)

If an invalid base address is passed, debug builds will assert. Release builds will just return instance number 0.

Parameters
baseThe I2C peripheral base address.
Returns
I2C instance number starting from 0.
static void I2C_MasterReset ( I2C_Type *  base)
inlinestatic

Restores the I2C master peripheral to reset conditions.

Parameters
baseThe I2C peripheral base address.
static void I2C_MasterEnable ( I2C_Type *  base,
bool  enable 
)
inlinestatic
Parameters
baseThe I2C peripheral base address.
enablePass true to enable or false to disable the specified I2C as master.
static uint32_t I2C_GetStatusFlags ( I2C_Type *  base)
inlinestatic

A bit mask with the state of all I2C status flags is returned. For each flag, the corresponding bit in the return value is set if the flag is asserted.

Parameters
baseThe I2C peripheral base address.
Returns
State of the status flags:
  • 1: related status flag is set.
  • 0: related status flag is not set.
See Also
_i2c_master_flags
static void I2C_MasterClearStatusFlags ( I2C_Type *  base,
uint32_t  statusMask 
)
inlinestatic

The following status register flags can be cleared:

Attempts to clear other flags has no effect.

Parameters
baseThe I2C peripheral base address.
statusMaskA bitmask of status flags that are to be cleared. The mask is composed of _i2c_master_flags enumerators OR'd together. You may pass the result of a previous call to I2C_GetStatusFlags().
See Also
_i2c_master_flags.
static void I2C_EnableInterrupts ( I2C_Type *  base,
uint32_t  interruptMask 
)
inlinestatic
Parameters
baseThe I2C peripheral base address.
interruptMaskBit mask of interrupts to enable. See _i2c_master_flags for the set of constants that should be OR'd together to form the bit mask.
static void I2C_DisableInterrupts ( I2C_Type *  base,
uint32_t  interruptMask 
)
inlinestatic
Parameters
baseThe I2C peripheral base address.
interruptMaskBit mask of interrupts to disable. See _i2c_master_flags for the set of constants that should be OR'd together to form the bit mask.
static uint32_t I2C_GetEnabledInterrupts ( I2C_Type *  base)
inlinestatic
Parameters
baseThe I2C peripheral base address.
Returns
A bitmask composed of _i2c_master_flags enumerators OR'd together to indicate the set of enabled interrupts.
void I2C_MasterSetBaudRate ( I2C_Type *  base,
uint32_t  baudRate_Bps,
uint32_t  srcClock_Hz 
)

The I2C master is automatically disabled and re-enabled as necessary to configure the baud rate. Do not call this function during a transfer, or the transfer is aborted.

Parameters
baseThe I2C peripheral base address.
srcClock_HzI2C functional clock frequency in Hertz.
baudRate_BpsRequested bus frequency in bits per second.
static bool I2C_MasterGetBusIdleState ( I2C_Type *  base)
inlinestatic

Requires the master mode to be enabled.

Parameters
baseThe I2C peripheral base address.
Return values
trueBus is busy.
falseBus is idle.
status_t I2C_MasterStart ( I2C_Type *  base,
uint8_t  address,
i2c_direction_t  direction 
)

This function is used to initiate a new master mode transfer by sending the START signal. The slave address is sent following the I2C START signal.

Parameters
baseI2C peripheral base pointer
address7-bit slave device address.
directionMaster transfer directions(transmit/receive).
Return values
kStatus_SuccessSuccessfully send the start signal.
kStatus_I2C_BusyCurrent bus is busy.
status_t I2C_MasterStop ( I2C_Type *  base)
Return values
kStatus_SuccessSuccessfully send the stop signal.
kStatus_I2C_TimeoutSend stop signal failed, timeout.
static status_t I2C_MasterRepeatedStart ( I2C_Type *  base,
uint8_t  address,
i2c_direction_t  direction 
)
inlinestatic
Parameters
baseI2C peripheral base pointer
address7-bit slave device address.
directionMaster transfer directions(transmit/receive).
Return values
kStatus_SuccessSuccessfully send the start signal.
kStatus_I2C_BusyCurrent bus is busy but not occupied by current I2C master.
status_t I2C_MasterWriteBlocking ( I2C_Type *  base,
const void *  txBuff,
size_t  txSize,
uint32_t  flags 
)

Sends up to txSize number of bytes to the previously addressed slave device. The slave may reply with a NAK to any byte in order to terminate the transfer early. If this happens, this function returns kStatus_I2C_Nak.

Parameters
baseThe I2C peripheral base address.
txBuffThe pointer to the data to be transferred.
txSizeThe length in bytes of the data to be transferred.
flagsTransfer control flag to control special behavior like suppressing start or stop, for normal transfers use kI2C_TransferDefaultFlag
Return values
kStatus_SuccessData was sent successfully.
kStatus_I2C_BusyAnother master is currently utilizing the bus.
kStatus_I2C_NakThe slave device sent a NAK in response to a byte.
kStatus_I2C_ArbitrationLostArbitration lost error.
status_t I2C_MasterReadBlocking ( I2C_Type *  base,
void *  rxBuff,
size_t  rxSize,
uint32_t  flags 
)
Parameters
baseThe I2C peripheral base address.
rxBuffThe pointer to the data to be transferred.
rxSizeThe length in bytes of the data to be transferred.
flagsTransfer control flag to control special behavior like suppressing start or stop, for normal transfers use kI2C_TransferDefaultFlag
Return values
kStatus_SuccessData was received successfully.
kStatus_I2C_BusyAnother master is currently utilizing the bus.
kStatus_I2C_NakThe slave device sent a NAK in response to a byte.
kStatus_I2C_ArbitrationLostArbitration lost error.
status_t I2C_MasterTransferBlocking ( I2C_Type *  base,
i2c_master_transfer_t *  xfer 
)
Note
The API does not return until the transfer succeeds or fails due to arbitration lost or receiving a NAK.
Parameters
baseI2C peripheral base address.
xferPointer to the transfer structure.
Return values
kStatus_SuccessSuccessfully complete the data transmission.
kStatus_I2C_BusyPrevious transmission still not finished.
kStatus_I2C_TimeoutTransfer error, wait signal timeout.
kStatus_I2C_ArbitrationLostTransfer error, arbitration lost.
kStataus_I2C_NakTransfer error, receive NAK during transfer.
void I2C_MasterTransferCreateHandle ( I2C_Type *  base,
i2c_master_handle_t *  handle,
i2c_master_transfer_callback_t  callback,
void *  userData 
)

The creation of a handle is for use with the non-blocking APIs. Once a handle is created, there is not a corresponding destroy handle. If the user wants to terminate a transfer, the I2C_MasterTransferAbort() API shall be called.

Parameters
baseThe I2C peripheral base address.
[out]handlePointer to the I2C master driver handle.
callbackUser provided pointer to the asynchronous callback function.
userDataUser provided pointer to the application callback data.
status_t I2C_MasterTransferNonBlocking ( I2C_Type *  base,
i2c_master_handle_t *  handle,
i2c_master_transfer_t *  xfer 
)
Parameters
baseThe I2C peripheral base address.
handlePointer to the I2C master driver handle.
xferThe pointer to the transfer descriptor.
Return values
kStatus_SuccessThe transaction was started successfully.
kStatus_I2C_BusyEither another master is currently utilizing the bus, or a non-blocking transaction is already in progress.
status_t I2C_MasterTransferGetCount ( I2C_Type *  base,
i2c_master_handle_t *  handle,
size_t *  count 
)
Parameters
baseThe I2C peripheral base address.
handlePointer to the I2C master driver handle.
[out]countNumber of bytes transferred so far by the non-blocking transaction.
Return values
kStatus_Success
kStatus_I2C_Busy
status_t I2C_MasterTransferAbort ( I2C_Type *  base,
i2c_master_handle_t *  handle 
)
Note
It is not safe to call this function from an IRQ handler that has a higher priority than the I2C peripheral's IRQ priority.
Parameters
baseThe I2C peripheral base address.
handlePointer to the I2C master driver handle.
Return values
kStatus_SuccessA transaction was successfully aborted.
kStatus_I2C_TimeoutTimeout during polling for flags.
void I2C_MasterTransferHandleIRQ ( I2C_Type *  base,
i2c_master_handle_t *  handle 
)
Note
This function does not need to be called unless you are reimplementing the nonblocking API's interrupt handler routines to add special functionality.
Parameters
baseThe I2C peripheral base address.
handlePointer to the I2C master driver handle.