Overview

The MCUXpresso SDK provides a driver for the IMU module of MCUXpresso SDK devices.

Data Structures
struct	IMU_Type
	IMU register structure. More...

Macros
#define	IMU_RX_FIFO_EMPTY(link) (0UL != (((IMU_Type *)IMU_PEER_CPU_BASE(link))->MSG_FIFO_STATUS & IMU_MSG_FIFO_STATUS_MSG_FIFO_EMPTY_MASK))
	Get Rx FIFO empty status. More...

#define	IMU_ERR_TX_FIFO_LOCKED (-1L)
	IMU driver returned error value. More...

#define	IMU_MSG_FIFO_MAX_COUNT 16U
	Maximum message numbers in FIFO. More...

#define	IMU_MAX_MSG_FIFO_WATER_MARK (IMU_MSG_FIFO_MAX_COUNT - 1U)
	Maximum message FIFO warter mark. More...

Enumerations
enum	_imu_status_flags
	IMU status flags. More...

enum	_imu_interrupts
	IMU interrupt. More...

Driver version
#define	FSL_IMU_DRIVER_VERSION (MAKE_VERSION(2, 1, 1))
	IMU driver version. More...

IMU initialization.
status_t	IMU_Init (imu_link_t link)
	Initializes the IMU module. More...

void	IMU_Deinit (imu_link_t link)
	De-initializes the IMU module. More...

IMU Message
static void	IMU_WriteMsg (imu_link_t link, uint32_t msg)
	Write one message to TX FIFO. More...

static uint32_t	IMU_ReadMsg (imu_link_t link)
	Read one message from RX FIFO. More...

int32_t	IMU_SendMsgsBlocking (imu_link_t link, const uint32_t *msgs, int32_t msgCount, bool lockSendFifo)
	Blocking to send messages. More...

int32_t	IMU_TrySendMsgs (imu_link_t link, const uint32_t *msgs, int32_t msgCount, bool lockSendFifo)
	Try to send messages. More...

int32_t	IMU_TryReceiveMsgs (imu_link_t link, uint32_t msgs, int32_t desiredMsgCount, bool needAckLock)
	Try to receive messages. More...

int32_t	IMU_ReceiveMsgsBlocking (imu_link_t link, uint32_t msgs, int32_t desiredMsgCount, bool needAckLock)
	Blocking to receive messages. More...

int32_t	IMU_SendMsgPtrBlocking (imu_link_t link, uint32_t msgPtr, bool lockSendFifo)
	Blocking to send messages pointer. More...

static void	IMU_LockSendFifo (imu_link_t link, bool lock)
	Lock or unlock the TX FIFO. More...

void	IMU_FlushSendFifo (imu_link_t link)
	Flush the send FIFO. More...

static void	IMU_SetSendFifoWaterMark (imu_link_t link, uint8_t waterMark)
	Set send FIFO warter mark. More...

static uint32_t	IMU_GetReceivedMsgCount (imu_link_t link)
	Get the message count in receive FIFO. More...

static uint32_t	IMU_GetSendFifoEmptySpace (imu_link_t link)
	Get the empty slot in send FIFO. More...

Status and Interrupt.
uint32_t	IMU_GetStatusFlags (imu_link_t link)
	Gets the IMU status flags. More...

static void	IMU_ClearPendingInterrupts (imu_link_t link, uint32_t mask)
	Clear the IMU IRQ. More...

Data Structure Documentation

struct IMU_Type

Macro Definition Documentation

#define FSL_IMU_DRIVER_VERSION (MAKE_VERSION(2, 1, 1))

#define IMU_RX_FIFO_EMPTY ( link ) (0UL != (((IMU_Type *)IMU_PEER_CPU_BASE(link))->MSG_FIFO_STATUS & IMU_MSG_FIFO_STATUS_MSG_FIFO_EMPTY_MASK))

#define IMU_ERR_TX_FIFO_LOCKED (-1L)

#define IMU_MSG_FIFO_MAX_COUNT 16U

#define IMU_MAX_MSG_FIFO_WATER_MARK (IMU_MSG_FIFO_MAX_COUNT - 1U)

Enumeration Type Documentation

enum _imu_status_flags

enum _imu_interrupts

Function Documentation

status_t IMU_Init ( imu_link_t link )

This function sets IMU to initialized state, including:

Flush the send FIFO.
Unlock the send FIFO.
Set the water mark to (IMU_MAX_MSG_FIFO_WATER_MARK)
Flush the read FIFO.

Parameters

link IMU link.

Return values

kStatus_InvalidArgument	The link is invalid.
kStatus_Success	Initialized successfully.

void IMU_Deinit ( imu_link_t link )

Parameters

link IMU link.

static void IMU_WriteMsg	(	imu_link_t	link,
		uint32_t	msg
	)

inlinestatic

This function writes message to the TX FIFO, user need to make sure there is empty space in the TX FIFO, and TX FIFO not locked before calling this function.

Parameters

link	IMU link.
msg	The message to send.

static uint32_t IMU_ReadMsg ( imu_link_t link )

inlinestatic

User need to make sure there is available message in the RX FIFO.

Parameters

link IMU link.

Returns: The message.

int32_t IMU_SendMsgsBlocking	(	imu_link_t	link,
		const uint32_t *	msgs,
		int32_t	msgCount,
		bool	lockSendFifo
	)

This function blocks until all messages have been filled to TX FIFO.

If the TX FIFO is locked, this function returns IMU_ERR_TX_FIFO_LOCKED.
If TX FIFO not locked, this function waits the available empty slot in TX FIFO, and fills the message to TX FIFO.
To lock TX FIFO after filling all messages, set lockSendFifo to true.

Parameters

link	IMU link.
msgs	The messages to send.
msgCount	Message count, one message is a 32-bit word.
lockSendFifo	If set to true, the TX FIFO is locked after all messages filled to TX FIFO.

Returns: If TX FIFO is locked, this function returns IMU_ERR_TX_FIFO_LOCKED, otherwise, this function returns the actual message count sent out, it equals msgCount because this function is blocking function, it returns until all messages have been filled into TX FIFO.

int32_t IMU_TrySendMsgs	(	imu_link_t	link,
		const uint32_t *	msgs,
		int32_t	msgCount,
		bool	lockSendFifo
	)

This function is similar with IMU_SendMsgsBlocking, the difference is, this function tries to send as many as possible, if there is not enough empty slot in TX FIFO, this function fills messages to available empty slots and returns how many messages have been filled.

If the TX FIFO is locked, this function returns IMU_ERR_TX_FIFO_LOCKED.
If TX FIFO not locked, this function fills messages to TX FIFO empty slot, and returns how many messages have been filled.
If lockSendFifo is set to true, TX FIFO is locked after all messages have been filled to TX FIFO. In other word, TX FIFO is locked if the function return value equals msgCount, when lockSendFifo set to true.

Parameters

link	IMU link.
msgs	The messages to send.
msgCount	Message count, one message is a 32-bit word.
lockSendFifo	If set to true, the TX FIFO is locked after all messages filled to TX FIFO.

Returns: If TX FIFO is locked, this function returns IMU_ERR_TX_FIFO_LOCKED, otherwise, this function returns the actual message count sent out.

int32_t IMU_TryReceiveMsgs	(	imu_link_t	link,
		uint32_t *	msgs,
		int32_t	desiredMsgCount,
		bool *	needAckLock
	)

This function tries to read messages from RX FIFO. It reads the messages already exists in RX FIFO and returns the actual read count.

If the RX FIFO has enough messages, this function reads the messages and returns.
If the RX FIFO does not have enough messages, this function the messages in RX FIFO and returns the actual read count.
During message reading, if RX FIFO is empty and locked, in this case peer CPU will not send message until current CPU send lock ack message. Then this function returns the message count actually received, and sets needAckLock to true to inform upper layer.

Parameters

link	IMU link.
msgs	The buffer to read messages.
desiredMsgCount	Desired read count, one message is a 32-bit word.
needAckLock	Upper layer should always check this value. When this is set to true by this function, upper layer should send lock ack message to peer CPU.

Returns: Count of messages actually received.

int32_t IMU_ReceiveMsgsBlocking	(	imu_link_t	link,
		uint32_t *	msgs,
		int32_t	desiredMsgCount,
		bool *	needAckLock
	)

This function blocks until all desired messages have been received or the RX FIFO is locked.

If the RX FIFO has enough messages, this function reads the messages and returns.
If the RX FIFO does not have enough messages, this function waits for the new messages.
During message reading, if RX FIFO is empty and locked, in this case peer CPU will not send message until current CPU send lock ack message. Then this function returns the message count actually received, and sets needAckLock to true to inform upper layer.

Parameters

link	IMU link.
msgs	The buffer to read messages.
desiredMsgCount	Desired read count, one message is a 32-bit word.
needAckLock	Upper layer should always check this value. When this is set to true by this function, upper layer should send lock ack message to peer CPU.

Returns: Count of messages actually received.

int32_t IMU_SendMsgPtrBlocking	(	imu_link_t	link,
		uint32_t	msgPtr,
		bool	lockSendFifo
	)

Compared with IMU_SendMsgsBlocking, this function fills message pointer to TX FIFO, but not the message content.

This function blocks until the message pointer is filled to TX FIFO.

If the TX FIFO is locked, this function returns IMU_ERR_TX_FIFO_LOCKED.
If TX FIFO not locked, this function waits the available empty slot in TX FIFO, and fills the message pointer to TX FIFO.
To lock TX FIFO after filling the message pointer, set lockSendFifo to true.

Parameters

link	IMU link.
msgPtr	The buffer pointer to message to send.
needAckLock	Upper layer should always check this value. When this is set to true by this function, upper layer should send lock ack message to peer CPU.

Return values

0	The message pointer set successfully.
IMU_ERR_TX_FIFO_LOCKED	The TX FIFO is locked, send failed.

static void IMU_LockSendFifo	(	imu_link_t	link,
		bool	lock
	)

inlinestatic

Parameters

link	IMU link.
lock	Use true to lock the FIFO, use false to unlock.

void IMU_FlushSendFifo ( imu_link_t link )

Flush all messages in send FIFO.

Parameters

link IMU link.

static void IMU_SetSendFifoWaterMark	(	imu_link_t	link,
		uint8_t	waterMark
	)

inlinestatic

The warter mark must be less than IMU_MAX_MSG_FIFO_WATER_MARK, i.e. 0 < waterMark <= IMU_MAX_MSG_FIFO_WATER_MARK.

Parameters

link	IMU link.
waterMark	Send FIFO warter mark.

static uint32_t IMU_GetReceivedMsgCount ( imu_link_t link )

inlinestatic

Parameters

link IMU link.

Returns: The message count in receive FIFO.

static uint32_t IMU_GetSendFifoEmptySpace ( imu_link_t link )

inlinestatic

Parameters

link IMU link.

Returns: The empty slot count in send FIFO.

uint32_t IMU_GetStatusFlags ( imu_link_t link )

Parameters

link IMU link.

Returns: Bit mask of the IMU status flags, see _imu_status_flags.

static void IMU_ClearPendingInterrupts	(	imu_link_t	link,
		uint32_t	mask
	)

inlinestatic

Parameters

link	IMU link.
mask	Bit mask of the interrupts to clear, see _imu_interrupts.

Overview

Data Structures

Macros

Enumerations

Driver version

IMU initialization.

IMU Message

Status and Interrupt.

Data Structure Documentation

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation