Overview

The MCUXpresso SDK provides a peripheral driver for the Direct Memory Access (DMA) of MCUXpresso SDK devices.

Typical use case

DMA Operation

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/dma

Files
file	fsl_dma.h

Data Structures
struct	dma_descriptor_t
	DMA descriptor structure. More...

struct	dma_xfercfg_t
	DMA transfer configuration. More...

struct	dma_channel_trigger_t
	DMA channel trigger. More...

struct	dma_transfer_config_t
	DMA transfer configuration. More...

struct	dma_handle_t
	DMA transfer handle structure. More...

Typedefs
typedef void(*	dma_callback )(struct _dma_handle handle, void userData, bool transferDone, uint32_t intmode)
	Define Callback function for DMA. More...

Enumerations
enum	dma_priority_t { kDMA_ChannelPriority0 = 0, kDMA_ChannelPriority1, kDMA_ChannelPriority2, kDMA_ChannelPriority3, kDMA_ChannelPriority4, kDMA_ChannelPriority5, kDMA_ChannelPriority6, kDMA_ChannelPriority7 }
	DMA channel priority. More...

enum	dma_irq_t { kDMA_IntA, kDMA_IntB, kDMA_IntError }
	DMA interrupt flags. More...

enum	dma_trigger_type_t { kDMA_NoTrigger = 0, kDMA_LowLevelTrigger = DMA_CHANNEL_CFG_HWTRIGEN(1) \| DMA_CHANNEL_CFG_TRIGTYPE(1), kDMA_HighLevelTrigger, kDMA_FallingEdgeTrigger = DMA_CHANNEL_CFG_HWTRIGEN(1), kDMA_RisingEdgeTrigger }
	DMA trigger type. More...

enum	dma_trigger_burst_t { kDMA_SingleTransfer = 0, kDMA_LevelBurstTransfer = DMA_CHANNEL_CFG_TRIGBURST(1), kDMA_EdgeBurstTransfer1 = DMA_CHANNEL_CFG_TRIGBURST(1), kDMA_EdgeBurstTransfer2, kDMA_EdgeBurstTransfer4, kDMA_EdgeBurstTransfer8, kDMA_EdgeBurstTransfer16, kDMA_EdgeBurstTransfer32, kDMA_EdgeBurstTransfer64, kDMA_EdgeBurstTransfer128, kDMA_EdgeBurstTransfer256, kDMA_EdgeBurstTransfer512, kDMA_EdgeBurstTransfer1024 }
	DMA trigger burst. More...

enum	dma_burst_wrap_t { kDMA_NoWrap = 0, kDMA_SrcWrap = DMA_CHANNEL_CFG_SRCBURSTWRAP(1), kDMA_DstWrap = DMA_CHANNEL_CFG_DSTBURSTWRAP(1), kDMA_SrcAndDstWrap }
	DMA burst wrapping. More...

enum	dma_transfer_type_t { kDMA_MemoryToMemory = 0x0U, kDMA_PeripheralToMemory, kDMA_MemoryToPeripheral, kDMA_StaticToStatic }
	DMA transfer type. More...

enum	_dma_transfer_status { kStatus_DMA_Busy = MAKE_STATUS(kStatusGroup_DMA, 0) }
	DMA transfer status. More...

Driver version
#define	FSL_DMA_DRIVER_VERSION (MAKE_VERSION(2, 0, 0))
	DMA driver version. More...

DMA initialization and De-initialization
void	DMA_Init (DMA_Type *base)
	Initializes DMA peripheral. More...

void	DMA_Deinit (DMA_Type *base)
	Deinitializes DMA peripheral. More...

DMA Channel Operation
static bool	DMA_ChannelIsActive (DMA_Type *base, uint32_t channel)
	Return whether DMA channel is processing transfer. More...

static void	DMA_EnableChannelInterrupts (DMA_Type *base, uint32_t channel)
	Enables the interrupt source for the DMA transfer. More...

static void	DMA_DisableChannelInterrupts (DMA_Type *base, uint32_t channel)
	Disables the interrupt source for the DMA transfer. More...

static void	DMA_EnableChannel (DMA_Type *base, uint32_t channel)
	Enable DMA channel. More...

static void	DMA_DisableChannel (DMA_Type *base, uint32_t channel)
	Disable DMA channel. More...

static void	DMA_EnableChannelPeriphRq (DMA_Type *base, uint32_t channel)
	Set PERIPHREQEN of channel configuration register. More...

static void	DMA_DisableChannelPeriphRq (DMA_Type *base, uint32_t channel)
	Get PERIPHREQEN value of channel configuration register. More...

void	DMA_ConfigureChannelTrigger (DMA_Type base, uint32_t channel, dma_channel_trigger_t trigger)
	Set trigger settings of DMA channel. More...

uint32_t	DMA_GetRemainingBytes (DMA_Type *base, uint32_t channel)
	Gets the remaining bytes of the current DMA descriptor transfer. More...

static void	DMA_SetChannelPriority (DMA_Type *base, uint32_t channel, dma_priority_t priority)
	Set priority of channel configuration register. More...

static dma_priority_t	DMA_GetChannelPriority (DMA_Type *base, uint32_t channel)
	Get priority of channel configuration register. More...

void	DMA_CreateDescriptor (dma_descriptor_t desc, dma_xfercfg_t xfercfg, void srcAddr, void dstAddr, void *nextDesc)
	Create application specific DMA descriptor to be used in a chain in transfer. More...

DMA Transactional Operation
void	DMA_AbortTransfer (dma_handle_t *handle)
	Abort running transfer by handle. More...

void	DMA_CreateHandle (dma_handle_t handle, DMA_Type base, uint32_t channel)
	Creates the DMA handle. More...

void	DMA_SetCallback (dma_handle_t handle, dma_callback callback, void userData)
	Installs a callback function for the DMA transfer. More...

void	DMA_PrepareTransfer (dma_transfer_config_t config, void srcAddr, void dstAddr, uint32_t byteWidth, uint32_t transferBytes, dma_transfer_type_t type, void nextDesc)
	Prepares the DMA transfer structure. More...

status_t	DMA_SubmitTransfer (dma_handle_t handle, dma_transfer_config_t config)
	Submits the DMA transfer request. More...

void	DMA_StartTransfer (dma_handle_t *handle)
	DMA start transfer. More...

void	DMA_HandleIRQ (void)
	DMA IRQ handler for descriptor transfer complete. More...

Data Structure Documentation

struct dma_descriptor_t

Data Fields
uint32_t	xfercfg
	Transfer configuration.

void *	srcEndAddr
	Last source address of DMA transfer.

void *	dstEndAddr
	Last destination address of DMA transfer.

void *	linkToNextDesc
	Address of next DMA descriptor in chain.

struct dma_xfercfg_t

Data Fields
bool	valid
	Descriptor is ready to transfer.

bool	reload
	Reload channel configuration register after current descriptor is exhausted.

bool	swtrig
	Perform software trigger. More...

bool	clrtrig
	Clear trigger.

bool	intA
	Raises IRQ when transfer is done and set IRQA status register flag.

bool	intB
	Raises IRQ when transfer is done and set IRQB status register flag.

uint8_t	byteWidth
	Byte width of data to transfer.

uint8_t	srcInc
	Increment source address by 'srcInc' x 'byteWidth'.

uint8_t	dstInc
	Increment destination address by 'dstInc' x 'byteWidth'.

uint16_t	transferCount
	Number of transfers.

Field Documentation

bool dma_xfercfg_t::swtrig

Transfer if fired when 'valid' is set

struct dma_channel_trigger_t

Data Fields
dma_trigger_type_t	type
	Select hardware trigger as edge triggered or level triggered. More...

dma_trigger_burst_t	burst
	Select whether hardware triggers cause a single or burst transfer. More...

dma_burst_wrap_t	wrap
	Select wrap type, source wrap or dest wrap, or both. More...

Field Documentation

dma_trigger_type_t dma_channel_trigger_t::type

dma_trigger_burst_t dma_channel_trigger_t::burst

dma_burst_wrap_t dma_channel_trigger_t::wrap

struct dma_transfer_config_t

Data Fields
uint8_t *	srcAddr
	Source data address.

uint8_t *	dstAddr
	Destination data address.

uint8_t *	nextDesc
	Chain custom descriptor.

dma_xfercfg_t	xfercfg
	Transfer options.

bool	isPeriph
	DMA transfer is driven by peripheral.

struct dma_handle_t

Data Fields
dma_callback	callback
	Callback function. More...

void *	userData
	Callback function parameter.

DMA_Type *	base
	DMA peripheral base address.

uint8_t	channel
	DMA channel number.

Field Documentation

dma_callback dma_handle_t::callback

Invoked when transfer of descriptor with interrupt flag finishes

Macro Definition Documentation

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

Version 2.0.0.

Typedef Documentation

typedef void(* dma_callback)(struct _dma_handle *handle, void *userData, bool transferDone, uint32_t intmode)

Enumeration Type Documentation

enum dma_priority_t

Enumerator
kDMA_ChannelPriority0	Highest channel priority - priority 0.
kDMA_ChannelPriority1	Channel priority 1.
kDMA_ChannelPriority2	Channel priority 2.
kDMA_ChannelPriority3	Channel priority 3.
kDMA_ChannelPriority4	Channel priority 4.
kDMA_ChannelPriority5	Channel priority 5.
kDMA_ChannelPriority6	Channel priority 6.
kDMA_ChannelPriority7	Lowest channel priority - priority 7.

enum dma_irq_t

Enumerator
kDMA_IntA	DMA interrupt flag A.
kDMA_IntB	DMA interrupt flag B.
kDMA_IntError	DMA interrupt flag error.

enum dma_trigger_type_t

Enumerator
kDMA_NoTrigger	Trigger is disabled.
kDMA_LowLevelTrigger	Low level active trigger.
kDMA_HighLevelTrigger	High level active trigger.
kDMA_FallingEdgeTrigger	Falling edge active trigger.
kDMA_RisingEdgeTrigger	Rising edge active trigger.

enum dma_trigger_burst_t

Enumerator
kDMA_SingleTransfer	Single transfer.
kDMA_LevelBurstTransfer	Burst transfer driven by level trigger.
kDMA_EdgeBurstTransfer1	Perform 1 transfer by edge trigger.
kDMA_EdgeBurstTransfer2	Perform 2 transfers by edge trigger.
kDMA_EdgeBurstTransfer4	Perform 4 transfers by edge trigger.
kDMA_EdgeBurstTransfer8	Perform 8 transfers by edge trigger.
kDMA_EdgeBurstTransfer16	Perform 16 transfers by edge trigger.
kDMA_EdgeBurstTransfer32	Perform 32 transfers by edge trigger.
kDMA_EdgeBurstTransfer64	Perform 64 transfers by edge trigger.
kDMA_EdgeBurstTransfer128	Perform 128 transfers by edge trigger.
kDMA_EdgeBurstTransfer256	Perform 256 transfers by edge trigger.
kDMA_EdgeBurstTransfer512	Perform 512 transfers by edge trigger.
kDMA_EdgeBurstTransfer1024	Perform 1024 transfers by edge trigger.

enum dma_burst_wrap_t

Enumerator
kDMA_NoWrap	Wrapping is disabled.
kDMA_SrcWrap	Wrapping is enabled for source.
kDMA_DstWrap	Wrapping is enabled for destination.
kDMA_SrcAndDstWrap	Wrapping is enabled for source and destination.

enum dma_transfer_type_t

Enumerator
kDMA_MemoryToMemory	Transfer from memory to memory (increment source and destination)
kDMA_PeripheralToMemory	Transfer from peripheral to memory (increment only destination)
kDMA_MemoryToPeripheral	Transfer from memory to peripheral (increment only source)
kDMA_StaticToStatic	Peripheral to static memory (do not increment source or destination)

enum _dma_transfer_status

Enumerator
kStatus_DMA_Busy	Channel is busy and can't handle the transfer request.

Function Documentation

void DMA_Init ( DMA_Type * base )

This function enable the DMA clock, set descriptor table and enable DMA peripheral.

Parameters

base	DMA peripheral base address.

void DMA_Deinit ( DMA_Type * base )

This function gates the DMA clock.

Parameters

base	DMA peripheral base address.

static bool DMA_ChannelIsActive	(	DMA_Type *	base,
		uint32_t	channel
	)

inlinestatic

Parameters

base	DMA peripheral base address.
channel	DMA channel number.

Returns: True for active state, false otherwise.

static void DMA_EnableChannelInterrupts	(	DMA_Type *	base,
		uint32_t	channel
	)

inlinestatic

Parameters

base	DMA peripheral base address.
channel	DMA channel number.

static void DMA_DisableChannelInterrupts	(	DMA_Type *	base,
		uint32_t	channel
	)

inlinestatic

Parameters

base	DMA peripheral base address.
channel	DMA channel number.

static void DMA_EnableChannel	(	DMA_Type *	base,
		uint32_t	channel
	)

inlinestatic

Parameters

base	DMA peripheral base address.
channel	DMA channel number.

static void DMA_DisableChannel	(	DMA_Type *	base,
		uint32_t	channel
	)

inlinestatic

Parameters

base	DMA peripheral base address.
channel	DMA channel number.

static void DMA_EnableChannelPeriphRq	(	DMA_Type *	base,
		uint32_t	channel
	)

inlinestatic

Parameters

base	DMA peripheral base address.
channel	DMA channel number.

static void DMA_DisableChannelPeriphRq	(	DMA_Type *	base,
		uint32_t	channel
	)

inlinestatic

Parameters

base	DMA peripheral base address.
channel	DMA channel number.

Returns: True for enabled PeriphRq, false for disabled.

void DMA_ConfigureChannelTrigger	(	DMA_Type *	base,
		uint32_t	channel,
		dma_channel_trigger_t *	trigger
	)

Parameters

base	DMA peripheral base address.
channel	DMA channel number.
trigger	trigger configuration.

uint32_t DMA_GetRemainingBytes	(	DMA_Type *	base,
		uint32_t	channel
	)

Parameters

base	DMA peripheral base address.
channel	DMA channel number.

Returns: The number of bytes which have not been transferred yet.

static void DMA_SetChannelPriority	(	DMA_Type *	base,
		uint32_t	channel,
		dma_priority_t	priority
	)

inlinestatic

Parameters

base	DMA peripheral base address.
channel	DMA channel number.
priority	Channel priority value.

static dma_priority_t DMA_GetChannelPriority	(	DMA_Type *	base,
		uint32_t	channel
	)

inlinestatic

Parameters

base	DMA peripheral base address.
channel	DMA channel number.

Returns: Channel priority value.

void DMA_CreateDescriptor	(	dma_descriptor_t *	desc,
		dma_xfercfg_t *	xfercfg,
		void *	srcAddr,
		void *	dstAddr,
		void *	nextDesc
	)

Parameters

desc	DMA descriptor address.
xfercfg	Transfer configuration for DMA descriptor.
srcAddr	Address of last item to transmit
dstAddr	Address of last item to receive.
nextDesc	Address of next descriptor in chain.

void DMA_AbortTransfer ( dma_handle_t * handle )

This function aborts DMA transfer specified by handle.

Parameters

handle DMA handle pointer.

void DMA_CreateHandle	(	dma_handle_t *	handle,
		DMA_Type *	base,
		uint32_t	channel
	)

This function is called if using transaction API for DMA. This function initializes the internal state of DMA handle.

Parameters

handle	DMA handle pointer. The DMA handle stores callback function and parameters.
base	DMA peripheral base address.
channel	DMA channel number.

void DMA_SetCallback	(	dma_handle_t *	handle,
		dma_callback	callback,
		void *	userData
	)

This callback is called in DMA IRQ handler. Use the callback to do something after the current major loop transfer completes.

Parameters

handle	DMA handle pointer.
callback	DMA callback function pointer.
userData	Parameter for callback function.

void DMA_PrepareTransfer	(	dma_transfer_config_t *	config,
		void *	srcAddr,
		void *	dstAddr,
		uint32_t	byteWidth,
		uint32_t	transferBytes,
		dma_transfer_type_t	type,
		void *	nextDesc
	)

This function prepares the transfer configuration structure according to the user input.

Parameters

config	The user configuration structure of type dma_transfer_t.
srcAddr	DMA transfer source address.
dstAddr	DMA transfer destination address.
byteWidth	DMA transfer destination address width(bytes).
transferBytes	DMA transfer bytes to be transferred.
type	DMA transfer type.
nextDesc	Chain custom descriptor to transfer.

Note: The data address and the data width must be consistent. For example, if the SRC is 4 bytes, so the source address must be 4 bytes aligned, or it shall result in source address error(SAE).

status_t DMA_SubmitTransfer	(	dma_handle_t *	handle,
		dma_transfer_config_t *	config
	)

This function submits the DMA transfer request according to the transfer configuration structure. If the user submits the transfer request repeatedly, this function packs an unprocessed request as a TCD and enables scatter/gather feature to process it in the next time.

Parameters

handle	DMA handle pointer.
config	Pointer to DMA transfer configuration structure.

Return values

kStatus_DMA_Success	It means submit transfer request succeed.
kStatus_DMA_QueueFull	It means TCD queue is full. Submit transfer request is not allowed.
kStatus_DMA_Busy	It means the given channel is busy, need to submit request later.

void DMA_StartTransfer ( dma_handle_t * handle )

This function enables the channel request. User can call this function after submitting the transfer request or before submitting the transfer request.

Parameters

handle DMA handle pointer.

void DMA_HandleIRQ ( void )

This function clears the channel major interrupt flag and call the callback function if it is not NULL.

Overview

Typical use case

DMA Operation

Files

Data Structures

Typedefs

Enumerations

Driver version

DMA initialization and De-initialization

DMA Channel Operation

DMA Transactional Operation

Data Structure Documentation

Data Fields

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Data Fields

Field Documentation

Macro Definition Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation