Overview

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

Typical use case

DMAC Operation

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

Data Structures
struct	dmac_channel_transfer_config_t
	dmac channel transfer configuration More...

struct	dmac_config_t
	dmac configuration structure More...

struct	dmac_handle_t
	DMAC transfer handle structure. More...

Typedefs
typedef void(*	dmac_transfer_callback_t )(dmac_handle_t handle, void userData, uint32_t status)
	Define Callback function for DMAC. More...

Enumerations
enum	dmac_channel_transfer_type_t { kDMAC_ChannelTransferMemoryToMemory = 0x0U, kDMAC_ChannelTransferPeripheralToMemory, kDMAC_ChannelTransferMemoryToPeripheral }
	DMAC transfer type. More...

enum	_dmac_channel_interrupt_flag { kDMAC_ChannelInterruptFlagTransferComplete = 1U, kDMAC_ChannelInterruptBlockTransferComplete = 2U, kDMAC_ChannelInterruptFlagBusError = 4U, kDMAC_ChannelInterruptFlagAdressError = 8U }
	DMAC interrupt source. More...

enum	dmac_channel_t { kDMAC_Channel0 = 0U, kDMAC_Channel1 = 1U, kDMAC_Channel2 = 2U, kDMAC_Channel3 = 3U, kDMAC_Channel4 = 4U, kDMAC_Channel5 = 5U, kDMAC_Channel6 = 6U, kDMAC_Channel7 = 7U, kDMAC_Channel8 = 8U, kDMAC_Channel9 = 9U, kDMAC_Channel10 = 10U, kDMAC_Channel11 = 11U, kDMAC_Channel12 = 12U, kDMAC_Channel13 = 13U, kDMAC_Channel14 = 14U, kDMAC_Channel15 = 15U, kDMAC_Channel16 = 16U, kDMAC_Channel17 = 17U, kDMAC_Channel18 = 18U, kDMAC_Channel19 = 19U, kDMAC_Channel20 = 20U, kDMAC_Channel21 = 21U, kDMAC_Channel22 = 22U, kDMAC_Channel23 = 23U, kDMAC_Channel24 = 24U, kDMAC_Channel25 = 25U, kDMAC_Channel26 = 26U, kDMAC_Channel27 = 27U, kDMAC_Channel28 = 28U, kDMAC_Channel29 = 29U, kDMAC_Channel30 = 30U, kDMAC_Channel31 = 31U }
	dmac channel index More...

enum	dmac_channel_address_increment_type_t { kDMAC_ChannelAddressFix = 0U, kDMAC_ChannelAddressIncrement }
	DMAC transfer address increment definition. More...

enum	dmac_channel_transfer_width_t { kDMAC_ChannelTransferWidth8Bits = 1U, kDMAC_ChannelTransferWidth16Bits = 2U, kDMAC_ChannelTransferWidth32Bits = 4U }
	DMAC transfer width configuration. More...

enum	dmac_channel_burst_length_t { kDMAC_ChannelBurstLength1DataWidth = 0U, kDMAC_ChannelBurstLength4DataWidth, kDMAC_ChannelBurstLength8DataWidth, kDMAC_ChannelBurstLength16DataWidth }
	DMAC transfer burst length definition. More...

DMAC Initialization and De-initialization interfaces
void	DMAC_GetDefaultConfig (dmac_config_t *config)
	Get default dmac configuration. More...

void	DMAC_Init (DMAC_Type base, dmac_config_t config)
	DMAC initialization. More...

void	DMAC_Deinit (DMAC_Type *base)
	DMAC De-initialization. More...

DMAC channel functional interfaces
void	DMAC_GetChannelDefaultTransferConfig (dmac_channel_transfer_config_t transfer, void srcAddr, void *destAddr, dmac_channel_transfer_width_t transferWidth, dmac_channel_burst_length_t burstLength, uint32_t transferTotalBytes, dmac_channel_transfer_type_t transferType)
	Get channel default transfer configuration. More...

void	DMAC_SetChannelTransferConfig (DMAC_Type base, dmac_channel_t channel, dmac_channel_transfer_config_t transfer)
	DMAC set channel transfer configurations. More...

static void	DMAC_StartChannel (DMAC_Type *base, dmac_channel_t channel)
	start the dmac channel More...

static void	DMAC_StopChannel (DMAC_Type *base, dmac_channel_t channel)
	stop the dmac channel More...

void	DMAC_SetAckDelayCycle (DMAC_Type *base, uint32_t m2pAckDelayCycle)
	DMAC ack delay cycle for single transfer in M2P transfer type.Only called when the transfer type is M2P. More...

void	DMAC_SetPeripheralNumber (DMAC_Type *base, dmac_channel_t channel, dmac_peripheral_number_t peripheralNumber)
	DMAC set peripheral number. More...

DMAC channel interrupt Interfaces
void	DMAC_EnableChannelInterrupts (DMAC_Type *base, dmac_channel_t channel, uint32_t interruptsMask)
	enables the dmac channel interrupts More...

void	DMAC_DisableChannelInterrupts (DMAC_Type *base, dmac_channel_t channel, uint32_t interruptsMask)
	disables the dmac channel interrupts More...

DMAC channel Status Interfaces
uint32_t	DMAC_GetChannelInterruptStatus (DMAC_Type *base, dmac_channel_t channel)
	Gets the DMAC channel status. More...

void	DMAC_ClearChannelInterruptStatus (DMAC_Type *base, dmac_channel_t channel, uint32_t status)
	Clears the DMAC channel status. More...

DMAC Transactional Interfaces
void	DMAC_TransferCreateHandle (DMAC_Type base, dmac_handle_t handle, dmac_channel_t channel)
	Creates the DMAC channel handle. More...

void	DMAC_TransferSetCallback (dmac_handle_t handle, dmac_transfer_callback_t callback, void userData)
	Sets the DMAC Callback function. More...

status_t	DMAC_TransferSubmit (dmac_handle_t handle, dmac_channel_transfer_config_t transfer)
	Submits the DMAC transfer configurations. More...

void	DMAC_TransferStart (dmac_handle_t *handle)
	DMAC starts transfer. More...

void	DMAC_TransferStop (dmac_handle_t *handle)
	DMAC stops transfer. More...

void	DMAC_TransferHandleIRQ (DMAC_Type *base)
	DMAC IRQ handler for the transfer completion. More...

Data Structure Documentation

struct dmac_channel_transfer_config_t

The transfer configuration structure support full feature configuration of the transfer control descriptor.

Data Fields
void *	srcAddr
	source address

void *	destAddr
	destination address

dmac_channel_address_increment_type_t	srcAddrIncrementType
	Source address increment kDMAC_ChannelAddressFix: No change kDMAC_ChannelAddressIncrement: Increment

dmac_channel_address_increment_type_t	destAddrIncrementType
	Destination address increment kDMAC_ChannelAddressFix: No change kDMAC_ChannelAddressIncrement: Increment

dmac_channel_transfer_type_t	transferType
	Transfer type and flow control kDMAC_ChannelTransferMemoryToMemory: Memory to Memory kDMAC_ChannelTransferPeripheralToMemory: Memory to peripheral kDMAC_ChannelTransferMemoryToPeripheral: Peripheral to memory.

dmac_channel_burst_length_t	burstLength
	Burst transaction length kDMAC_ChannelBurstLength1DataWidth: 1 Data Width kDMAC_ChannelBurstLength4DataWidth: 4 Data Width kDMAC_ChannelBurstLength8DataWidth: 8 Data Width kDMAC_ChannelBurstLength16DataWidth: 16 Data Width

dmac_channel_transfer_width_t	transferWidth
	Transfer width kDMAC_ChannelTransferWidth8Bits: 8 bits kDMAC_ChannelTransferWidth16Bits: 16 bits kDMAC_ChannelTransferWidth32Bits: 32 bits.

uint32_t	transferTotalBytes
	Transfer totalbytes 0~8191bytes maximum transfer length (8k-1) bytes.

uint32_t	interruptMask
	Interrupt Mask.

struct dmac_config_t

Data Fields
uint32_t	m2pAckDelayCycle
	m2pAckDelayCycle for single write transaction to peripheral. More...

dmac_channel_transfer_config_t *	channelTransferConfig [FSL_FEATURE_MW_DMAC_MODULE_CHANNEL]
	channel transfer configuration pointer

dmac_peripheral_number_t	peripheralNumber [FSL_FEATURE_MW_DMAC_MODULE_CHANNEL]
	Peripheral Number Indicates the valid peripheral request number.The default value kDMAC_PeriphNum_None. More...

Field Documentation

uint32_t dmac_config_t::m2pAckDelayCycle

The value should be less than 1023, default value 12.

dmac_peripheral_number_t dmac_config_t::peripheralNumber[FSL_FEATURE_MW_DMAC_MODULE_CHANNEL]

struct _dmac_handle

handler for DMAC

Data Fields
volatile uint32_t	state
	channel transfer state

dmac_transfer_callback_t	callback
	callback function

void *	userData
	Callback function parameter. More...

DMAC_Type *	base
	DMAC peripheral base address. More...

dmac_channel_t	channel
	DMAC channel number. More...

Field Documentation

void* dmac_handle_t::userData

DMAC_Type* dmac_handle_t::base

dmac_channel_t dmac_handle_t::channel

Typedef Documentation

typedef void(* dmac_transfer_callback_t)(dmac_handle_t *handle, void *userData, uint32_t status)

Parameters

handle	DMAC handle pointer, users shall not touch the values inside.
userData	The callback user parameter pointer. Users can use this parameter to involve things users need to change in DMAC Callback function.
status	The mask of channel status . Users need to use the _dmac_channel_interrupt_status type. If the current loaded transfer done. In normal mode it means if all transfer done. In scatter gather mode, this parameter shows is the current transfer block in DMAC register is done.

Enumeration Type Documentation

enum dmac_channel_transfer_type_t

Enumerator
kDMAC_ChannelTransferMemoryToMemory	Transfer type from memory to memory assume that the both source and destination address are incremental.
kDMAC_ChannelTransferPeripheralToMemory	Transfer type peripher to memory assume that the source address is fixed.
kDMAC_ChannelTransferMemoryToPeripheral	Transfer type from memory to peripheral assume that the destination address is fixed.

enum _dmac_channel_interrupt_flag

Enumerator
kDMAC_ChannelInterruptFlagTransferComplete	Dmac transfer complete interrupt.
kDMAC_ChannelInterruptBlockTransferComplete	Block transfer complete interrupt.
kDMAC_ChannelInterruptFlagBusError	Bus Error interrupt.
kDMAC_ChannelInterruptFlagAdressError	Address Error interrupt.

enum dmac_channel_t

Enumerator
kDMAC_Channel0	channel 0 define, priority level 0, the highest priority
kDMAC_Channel1	channel 1 define, priority level 0, the highest priority
kDMAC_Channel2	channel 2 define, priority level 0, the highest priority
kDMAC_Channel3	channel 3 define, priority level 0, the highest priority
kDMAC_Channel4	channel 4 define, priority level 1
kDMAC_Channel5	channel 5 define, priority level 1
kDMAC_Channel6	channel 6 define, priority level 1
kDMAC_Channel7	channel 7 define, priority level 1
kDMAC_Channel8	channel 8 define, priority level 2
kDMAC_Channel9	channel 9 define, priority level 2
kDMAC_Channel10	channel 10 define, priority level 2
kDMAC_Channel11	channel 11 define, priority level 2
kDMAC_Channel12	channel 12 define, priority level 3, the lowest priority
kDMAC_Channel13	channel 13 define, priority level 3, the lowest priority
kDMAC_Channel14	channel 14 define, priority level 3, the lowest priority
kDMAC_Channel15	channel 15 define, priority level 3, the lowest priority
kDMAC_Channel16	channel 16 define, priority level 0, the highest priority
kDMAC_Channel17	channel 17 define, priority level 0, the highest priority
kDMAC_Channel18	channel 18 define, priority level 0, the highest priority
kDMAC_Channel19	channel 19 define, priority level 0, the highest priority
kDMAC_Channel20	channel 20 define, priority level 1
kDMAC_Channel21	channel 21 define, priority level 1
kDMAC_Channel22	channel 22 define, priority level 1
kDMAC_Channel23	channel 23 define, priority level 1
kDMAC_Channel24	channel 24 define, priority level 2
kDMAC_Channel25	channel 25 define, priority level 2
kDMAC_Channel26	channel 26 define, priority level 2
kDMAC_Channel27	channel 27 define, priority level 2
kDMAC_Channel28	channel 28 define, priority level 3, the lowest priority
kDMAC_Channel29	channel 29 define, priority level 3, the lowest priority
kDMAC_Channel30	channel 30 define, priority level 3, the lowest priority
kDMAC_Channel31	channel 31 define, priority level 3, the lowest priority

enum dmac_channel_address_increment_type_t

Enumerator
kDMAC_ChannelAddressFix	Address Fix.
kDMAC_ChannelAddressIncrement	Address increment.

enum dmac_channel_transfer_width_t

Enumerator
kDMAC_ChannelTransferWidth8Bits	Source/Destination data transfer width is 1 byte every time.
kDMAC_ChannelTransferWidth16Bits	Source/Destination data transfer width is 2 bytes every time.
kDMAC_ChannelTransferWidth32Bits	Source/Destination data transfer width is 4 bytes every time.

enum dmac_channel_burst_length_t

Enumerator
kDMAC_ChannelBurstLength1DataWidth	Maximum burst transaction length 1 data width.
kDMAC_ChannelBurstLength4DataWidth	Maximum burst transaction length 4 data width.
kDMAC_ChannelBurstLength8DataWidth	Maximum burst transaction length 8 data width.
kDMAC_ChannelBurstLength16DataWidth	Maximum burst transaction length 16 data width.

Function Documentation

void DMAC_GetDefaultConfig ( dmac_config_t * config )

Note: This function will reset all of the configuration structure members to zero firstly, then apply default configurations to the structure.

Parameters

config pointer to user's DMAC configure structure, see dmac_config_t for detail.

void DMAC_Init	(	DMAC_Type *	base,
		dmac_config_t *	config
	)

Parameters

base	DMAC peripheral base address.
config	pointer to user's DMAC config structure, see dmac_config_t for detail.

void DMAC_Deinit ( DMAC_Type * base )

Parameters

base	DMAC peripheral base address.

void DMAC_GetChannelDefaultTransferConfig	(	dmac_channel_transfer_config_t *	transfer,
		void *	srcAddr,
		void *	destAddr,
		dmac_channel_transfer_width_t	transferWidth,
		dmac_channel_burst_length_t	burstLength,
		uint32_t	transferTotalBytes,
		dmac_channel_transfer_type_t	transferType
	)

Parameters

transfer	pointer to user's DMAC channel configure structure, see dmac_channel_transfer_config_t for detail.
srcAddr	source address, must be byte address.
destAddr	destination address, must be byte address.
transferWidth	the number of bits are transferred in each read/write.
burstLength	burst transaction length.
transferTotalBytes	transfer totalbytes 0~8191bytes maximum transfer length (8k-1) bytes.
transferType	DMAC channel transfer type.

void DMAC_SetChannelTransferConfig	(	DMAC_Type *	base,
		dmac_channel_t	channel,
		dmac_channel_transfer_config_t *	transfer
	)

Parameters

base	DMAC peripheral base address.
channel	DMAC channel number.
transfer	pointer to user's DMAC channel configure structure,see dmac_channel_transfer_config_t for detail.

static void DMAC_StartChannel	(	DMAC_Type *	base,
		dmac_channel_t	channel
	)

inlinestatic

Parameters

base	DMAC peripheral base address.
channel	DMAC channel number.

static void DMAC_StopChannel	(	DMAC_Type *	base,
		dmac_channel_t	channel
	)

inlinestatic

Parameters

base	DMAC peripheral base address.
channel	DMAC channel number.

void DMAC_SetAckDelayCycle	(	DMAC_Type *	base,
		uint32_t	m2pAckDelayCycle
	)

Parameters

base	DMAC peripheral base address.
m2pAckDelayCycle	for single write transaction to peripheral. The value should be less than 1023, default value 12.

void DMAC_SetPeripheralNumber	(	DMAC_Type *	base,
		dmac_channel_t	channel,
		dmac_peripheral_number_t	peripheralNumber
	)

Parameters

base	DMAC peripheral base address.
channel	DMAC channel number.
peripheralNumber	Indicates the valid peripheral request number, default value kDMAC_PeriphNum_None, see dmac_peripheral_number_t for detail.

void DMAC_EnableChannelInterrupts	(	DMAC_Type *	base,
		dmac_channel_t	channel,
		uint32_t	interruptsMask
	)

Parameters

base	DMAC peripheral base address.
channel	DMAC channel number.
interruptsMask	the mask is a logical OR of enumerator members see _dmac_channel_interrupt_flag.

void DMAC_DisableChannelInterrupts	(	DMAC_Type *	base,
		dmac_channel_t	channel,
		uint32_t	interruptsMask
	)

Parameters

base	DMAC peripheral base address.
channel	DMAC channel number.
interruptsMask	the mask is a logical OR of enumerator members see _dmac_channel_interrupt_flag.

uint32_t DMAC_GetChannelInterruptStatus	(	DMAC_Type *	base,
		dmac_channel_t	channel
	)

Parameters

base	DMAC peripheral base address.
channel	DMAC channel number.

Return values

The	mask of channel status. Users need to use the _dmac_channel_interrupt_flag type to decode the return variables.

void DMAC_ClearChannelInterruptStatus	(	DMAC_Type *	base,
		dmac_channel_t	channel,
		uint32_t	status
	)

Parameters

base	DMAC peripheral base address.
channel	DMAC channel number.
status	The mask of channel status to be cleared. Users need to use the defined _dmac_channel_interrupt_flag type.

void DMAC_TransferCreateHandle	(	DMAC_Type *	base,
		dmac_handle_t *	handle,
		dmac_channel_t	channel
	)

This function is called if using the transactional API for DMAC. This function initializes the internal state of the DMAC handle.

Parameters

base	DMAC peripheral base address.
handle	DMAC handle pointer. The DMAC handle stores Callback function and parameters.
channel	DMAC channel number.

void DMAC_TransferSetCallback	(	dmac_handle_t *	handle,
		dmac_transfer_callback_t	callback,
		void *	userData
	)

This callback is called in the DMAC IRQ handler. Use the callback to do something after the current transfer complete.

Parameters

handle	DMAC handle pointer.
callback	DMAC callback function pointer.
userData	Parameter for callback function. If it is not needed, just set to NULL.

status_t DMAC_TransferSubmit	(	dmac_handle_t *	handle,
		dmac_channel_transfer_config_t *	transfer
	)

Parameters

handle	DMAC handle pointer
transfer	pointer to user's DMAC channel configure structure,see dmac_channel_transfer_config_t for detail.

Return values

kStatus_Success	It means submit transfer request succeed
kStatus_Fail	It means submit transfer request failed

void DMAC_TransferStart ( dmac_handle_t * handle )

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

Parameters

handle DMAC handle pointer.

void DMAC_TransferStop ( dmac_handle_t * handle )

This function disables the channel request to pause the transfer. Users can call DMAC_StartTransfer() again to resume the transfer.

Parameters

handle DMAC handle pointer.

void DMAC_TransferHandleIRQ ( DMAC_Type * base )

Parameters

base	DMAC peripheral base address.

Overview

Typical use case

DMAC Operation

Data Structures

Typedefs

Enumerations

DMAC Initialization and De-initialization interfaces

DMAC channel functional interfaces

DMAC channel interrupt Interfaces

DMAC channel Status Interfaces

DMAC Transactional Interfaces

Data Structure Documentation

Data Fields

Data Fields

Field Documentation

Data Fields

Field Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation