DSPI DMA Driver

Overview

This section describes the programming interface of the DSPI Peripheral driver. The DSPI driver configures DSPI module and provides the functional and transactional interfaces to build the DSPI application.

Data Structures
struct	dspi_master_dma_handle_t
	DSPI master DMA transfer handle structure used for transactional API. More...
struct	dspi_slave_dma_handle_t
	DSPI slave DMA transfer handle structure used for transactional API. More...

Typedefs
typedef void(*	dspi_master_dma_transfer_callback_t )(SPI_Type *base, dspi_master_dma_handle_t *handle, status_t status, void *userData)
	Completion callback function pointer type. More...
typedef void(*	dspi_slave_dma_transfer_callback_t )(SPI_Type *base, dspi_slave_dma_handle_t *handle, status_t status, void *userData)
	Completion callback function pointer type. More...

Functions
void	DSPI_MasterTransferCreateHandleDMA (SPI_Type *base, dspi_master_dma_handle_t *handle, dspi_master_dma_transfer_callback_t callback, void *userData, dma_handle_t *dmaRxRegToRxDataHandle, dma_handle_t *dmaTxDataToIntermediaryHandle, dma_handle_t *dmaIntermediaryToTxRegHandle)
	Initializes the DSPI master DMA handle. More...
status_t	DSPI_MasterTransferDMA (SPI_Type *base, dspi_master_dma_handle_t *handle, dspi_transfer_t *transfer)
	DSPI master transfers data using DMA. More...
void	DSPI_MasterTransferAbortDMA (SPI_Type *base, dspi_master_dma_handle_t *handle)
	DSPI master aborts a transfer which is using DMA. More...
status_t	DSPI_MasterTransferGetCountDMA (SPI_Type *base, dspi_master_dma_handle_t *handle, size_t *count)
	Gets the master DMA transfer remaining bytes. More...
void	DSPI_SlaveTransferCreateHandleDMA (SPI_Type *base, dspi_slave_dma_handle_t *handle, dspi_slave_dma_transfer_callback_t callback, void *userData, dma_handle_t *dmaRxRegToRxDataHandle, dma_handle_t *dmaTxDataToTxRegHandle)
	Initializes the DSPI slave DMA handle. More...
status_t	DSPI_SlaveTransferDMA (SPI_Type *base, dspi_slave_dma_handle_t *handle, dspi_transfer_t *transfer)
	DSPI slave transfers data using DMA. More...
void	DSPI_SlaveTransferAbortDMA (SPI_Type *base, dspi_slave_dma_handle_t *handle)
	DSPI slave aborts a transfer which is using DMA. More...
status_t	DSPI_SlaveTransferGetCountDMA (SPI_Type *base, dspi_slave_dma_handle_t *handle, size_t *count)
	Gets the slave DMA transfer remaining bytes. More...

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Data Structure Documentation

struct _dspi_master_dma_handle

Forward declaration of the DSPI DMA master handle typedefs.

Data Fields
uint32_t	bitsPerFrame
	The desired number of bits per frame. More...
volatile uint32_t	command
	The desired data command. More...
volatile uint32_t	lastCommand
	The desired last data command. More...
uint8_t	fifoSize
	FIFO dataSize. More...
volatile bool	isPcsActiveAfterTransfer
	Indicates whether the PCS signal keeps active after the last frame transfer. More...
volatile bool	isThereExtraByte
	Indicates whether there is an extra byte. More...
uint8_t *volatile	txData
	Send buffer. More...
uint8_t *volatile	rxData
	Receive buffer. More...
volatile size_t	remainingSendByteCount
	A number of bytes remaining to send. More...
volatile size_t	remainingReceiveByteCount
	A number of bytes remaining to receive. More...
size_t	totalByteCount
	A number of transfer bytes.
uint32_t	rxBuffIfNull
	Used if there is not rxData for DMA purpose. More...
uint32_t	txBuffIfNull
	Used if there is not txData for DMA purpose. More...
volatile uint8_t	state
	DSPI transfer state, see _dspi_transfer_state. More...
dspi_master_dma_transfer_callback_t	callback
	Completion callback. More...
void *	userData
	Callback user data. More...
dma_handle_t *	dmaRxRegToRxDataHandle
	dma_handle_t handle point used for RxReg to RxData buff
dma_handle_t *	dmaTxDataToIntermediaryHandle
	dma_handle_t handle point used for TxData to Intermediary
dma_handle_t *	dmaIntermediaryToTxRegHandle
	dma_handle_t handle point used for Intermediary to TxReg

Field Documentation

uint32_t dspi_master_dma_handle_t::bitsPerFrame

volatile uint32_t dspi_master_dma_handle_t::command

volatile uint32_t dspi_master_dma_handle_t::lastCommand

uint8_t dspi_master_dma_handle_t::fifoSize

volatile bool dspi_master_dma_handle_t::isPcsActiveAfterTransfer

volatile bool dspi_master_dma_handle_t::isThereExtraByte

uint8_t* volatile dspi_master_dma_handle_t::txData

uint8_t* volatile dspi_master_dma_handle_t::rxData

volatile size_t dspi_master_dma_handle_t::remainingSendByteCount

volatile size_t dspi_master_dma_handle_t::remainingReceiveByteCount

uint32_t dspi_master_dma_handle_t::rxBuffIfNull

uint32_t dspi_master_dma_handle_t::txBuffIfNull

volatile uint8_t dspi_master_dma_handle_t::state

dspi_master_dma_transfer_callback_t dspi_master_dma_handle_t::callback

void* dspi_master_dma_handle_t::userData

struct _dspi_slave_dma_handle

Forward declaration of the DSPI DMA slave handle typedefs.

Data Fields
uint32_t	bitsPerFrame
	Desired number of bits per frame. More...
volatile bool	isThereExtraByte
	Indicates whether there is an extra byte. More...
uint8_t *volatile	txData
	A send buffer. More...
uint8_t *volatile	rxData
	A receive buffer. More...
volatile size_t	remainingSendByteCount
	A number of bytes remaining to send. More...
volatile size_t	remainingReceiveByteCount
	A number of bytes remaining to receive. More...
size_t	totalByteCount
	A number of transfer bytes.
uint32_t	rxBuffIfNull
	Used if there is not rxData for DMA purpose. More...
uint32_t	txBuffIfNull
	Used if there is not txData for DMA purpose. More...
uint32_t	txLastData
	Used if there is an extra byte when 16 bits per frame for DMA purpose. More...
volatile uint8_t	state
	DSPI transfer state. More...
uint32_t	errorCount
	Error count for the slave transfer. More...
dspi_slave_dma_transfer_callback_t	callback
	Completion callback. More...
void *	userData
	Callback user data. More...
dma_handle_t *	dmaRxRegToRxDataHandle
	dma_handle_t handle point used for RxReg to RxData buff
dma_handle_t *	dmaTxDataToTxRegHandle
	dma_handle_t handle point used for TxData to TxReg

Field Documentation

uint32_t dspi_slave_dma_handle_t::bitsPerFrame

volatile bool dspi_slave_dma_handle_t::isThereExtraByte

uint8_t* volatile dspi_slave_dma_handle_t::txData

uint8_t* volatile dspi_slave_dma_handle_t::rxData

volatile size_t dspi_slave_dma_handle_t::remainingSendByteCount

volatile size_t dspi_slave_dma_handle_t::remainingReceiveByteCount

uint32_t dspi_slave_dma_handle_t::rxBuffIfNull

uint32_t dspi_slave_dma_handle_t::txBuffIfNull

uint32_t dspi_slave_dma_handle_t::txLastData

volatile uint8_t dspi_slave_dma_handle_t::state

uint32_t dspi_slave_dma_handle_t::errorCount

dspi_slave_dma_transfer_callback_t dspi_slave_dma_handle_t::callback

void* dspi_slave_dma_handle_t::userData

Typedef Documentation

typedef void(* dspi_master_dma_transfer_callback_t)(SPI_Type *base, dspi_master_dma_handle_t *handle, status_t status, void *userData)

Parameters

base	DSPI peripheral base address.
handle	Pointer to the handle for the DSPI master.
status	Success or error code describing whether the transfer completed.
userData	Arbitrary pointer-dataSized value passed from the application.

typedef void(* dspi_slave_dma_transfer_callback_t)(SPI_Type *base, dspi_slave_dma_handle_t *handle, status_t status, void *userData)

Parameters

base	DSPI peripheral base address.
handle	Pointer to the handle for the DSPI slave.
status	Success or error code describing whether the transfer completed.
userData	Arbitrary pointer-dataSized value passed from the application.

Function Documentation

void DSPI_MasterTransferCreateHandleDMA	(	SPI_Type *	base,
		dspi_master_dma_handle_t *	handle,
		dspi_master_dma_transfer_callback_t	callback,
		void *	userData,
		dma_handle_t *	dmaRxRegToRxDataHandle,
		dma_handle_t *	dmaTxDataToIntermediaryHandle,
		dma_handle_t *	dmaIntermediaryToTxRegHandle
	)

This function initializes the DSPI DMA handle which can be used for other DSPI transactional APIs. Usually, for a specified DSPI instance, call this API once to get the initialized handle.

Note that DSPI DMA has a separated (Rx and Tx as two sources) or shared (Rx and Tx is the same source) DMA request source. (1) For a separated DMA request source, enable and set the Rx DMAMUX source for dmaRxRegToRxDataHandle and Tx DMAMUX source for dmaIntermediaryToTxRegHandle. (2) For a shared DMA request source, enable and set the Rx/Rx DMAMUX source for dmaRxRegToRxDataHandle.

Parameters

base	DSPI peripheral base address.
handle	DSPI handle pointer to dspi_master_dma_handle_t.
callback	DSPI callback.
userData	A callback function parameter.
dmaRxRegToRxDataHandle	dmaRxRegToRxDataHandle pointer to dma_handle_t.
dmaTxDataToIntermediaryHandle	dmaTxDataToIntermediaryHandle pointer to dma_handle_t.
dmaIntermediaryToTxRegHandle	dmaIntermediaryToTxRegHandle pointer to dma_handle_t.

status_t DSPI_MasterTransferDMA	(	SPI_Type *	base,
		dspi_master_dma_handle_t *	handle,
		dspi_transfer_t *	transfer
	)

This function transfers data using DMA. This is a non-blocking function, which returns right away. When all data is transferred, the callback function is called.

Note that the master DMA transfer does not support the transfer_size of 1 when the bitsPerFrame is greater than 8.

Parameters

base	DSPI peripheral base address.
handle	A pointer to the dspi_master_dma_handle_t structure which stores the transfer state.
transfer	A pointer to the dspi_transfer_t structure.

Returns

status of status_t.

void DSPI_MasterTransferAbortDMA	(	SPI_Type *	base,
		dspi_master_dma_handle_t *	handle
	)

This function aborts a transfer which is using DMA.

Parameters

base	DSPI peripheral base address.
handle	A pointer to the dspi_master_dma_handle_t structure which stores the transfer state.

status_t DSPI_MasterTransferGetCountDMA	(	SPI_Type *	base,
		dspi_master_dma_handle_t *	handle,
		size_t *	count
	)

This function gets the master DMA transfer remaining bytes.

Parameters

base	DSPI peripheral base address.
handle	A pointer to the dspi_master_dma_handle_t structure which stores the transfer state.
count	A number of bytes transferred by the non-blocking transaction.

Returns

status of status_t.

void DSPI_SlaveTransferCreateHandleDMA	(	SPI_Type *	base,
		dspi_slave_dma_handle_t *	handle,
		dspi_slave_dma_transfer_callback_t	callback,
		void *	userData,
		dma_handle_t *	dmaRxRegToRxDataHandle,
		dma_handle_t *	dmaTxDataToTxRegHandle
	)

This function initializes the DSPI DMA handle which can be used for other DSPI transactional APIs. Usually, for a specified DSPI instance, call this API once to get the initialized handle.

Note that DSPI DMA has a separated (Rx and Tx as two sources) or shared (Rx and Tx is the same source) DMA request source. (1) For a separated DMA request source, enable and set the Rx DMAMUX source for dmaRxRegToRxDataHandle and Tx DMAMUX source for dmaTxDataToTxRegHandle. (2) For a shared DMA request source, enable and set the Rx/Rx DMAMUX source for dmaRxRegToRxDataHandle.

Parameters

base	DSPI peripheral base address.
handle	DSPI handle pointer to dspi_slave_dma_handle_t.
callback	DSPI callback.
userData	A callback function parameter.
dmaRxRegToRxDataHandle	dmaRxRegToRxDataHandle pointer to dma_handle_t.
dmaTxDataToTxRegHandle	dmaTxDataToTxRegHandle pointer to dma_handle_t.

status_t DSPI_SlaveTransferDMA	(	SPI_Type *	base,
		dspi_slave_dma_handle_t *	handle,
		dspi_transfer_t *	transfer
	)

This function transfers data using DMA. This is a non-blocking function, which returns right away. When all data is transferred, the callback function is called.

Note that the slave DMA transfer does not support the transfer_size of 1 when the bitsPerFrame is greater than eight.

Parameters

base	DSPI peripheral base address.
handle	A pointer to the dspi_slave_dma_handle_t structure which stores the transfer state.
transfer	A pointer to the dspi_transfer_t structure.

Returns

status of status_t.

void DSPI_SlaveTransferAbortDMA	(	SPI_Type *	base,
		dspi_slave_dma_handle_t *	handle
	)

This function aborts a transfer which is using DMA.

Parameters

base	DSPI peripheral base address.
handle	A pointer to the dspi_slave_dma_handle_t structure which stores the transfer state.

status_t DSPI_SlaveTransferGetCountDMA	(	SPI_Type *	base,
		dspi_slave_dma_handle_t *	handle,
		size_t *	count
	)

This function gets the slave DMA transfer remaining bytes.

Parameters

base	DSPI peripheral base address.
handle	A pointer to the dspi_slave_dma_handle_t structure which stores the transfer state.
count	A number of bytes transferred by the non-blocking transaction.

Returns

status of status_t.