Detailed Description

Direct Memory Access (DMA) Peripheral API.

These DMA access functions provide basic support for the following types of DMA cycles:

Basic, used for transferring data between memory and peripherals.
Auto-request, used for transferring data between memory locations.
Ping-pong, used for for continuous transfer of data between memory and peripherals, automatically toggling between primary and alternate descriptors.
Memory scatter-gather, used for transferring a number of buffers between memory locations.
Peripheral scatter-gather, used for transferring a number of buffers between memory and peripherals.

A basic understanding of the DMA controller is assumed. Please refer to the reference manual for further details.

The term 'descriptor' is used as a synonym to the 'channel control data structure' term.

In order to use the DMA controller, the initialization function must have been executed once (normally during system init):

* DMA_Init();
*

Then, normally a user of a DMA channel configures the channel:

* DMA_CfgChannel();
*

The channel configuration only has to be done once, if reusing the channel for the same purpose later.

In order to set up a DMA cycle, the primary and/or alternate descriptor has to be set up as indicated below.

For basic or auto-request cycles, use once on either primary or alternate descriptor:

* DMA_CfgDescr();
*

For ping-pong cycles, configure both primary or alternate descriptors:

* DMA_CfgDescr(); // Primary descriptor config
* DMA_CfgDescr(); // Alternate descriptor config
*

For scatter-gather cycles, the alternate descriptor array must be programmed:

* // 'n' is the number of scattered buffers
* // 'descr' points to the start of the alternate descriptor array
*
* // Fill in 'cfg'
* DMA_CfgDescrScatterGather(descr, 0, cfg);
* // Fill in 'cfg'
* DMA_CfgDescrScatterGather(descr, 1, cfg);
* :
* // Fill in 'cfg'
* DMA_CfgDescrScatterGather(descr, n - 1, cfg);
*

In many cases, the descriptor configuration only has to be done once, if re-using the channel for the same type of DMA cycles later.

In order to activate the DMA cycle, use the respective DMA_Activate...() function.

For ping-pong DMA cycles, use DMA_RefreshPingPong() from the callback to prepare the completed descriptor for reuse. Notice that the refresh must be done prior to the other active descriptor completes, otherwise the ping-pong DMA cycle will halt.

Data Structures
struct	DMA_CB_TypeDef
	Callback structure that can be used to define DMA complete actions. More...

struct	DMA_CfgChannel_TypeDef

struct	DMA_CfgDescr_TypeDef

struct	DMA_CfgDescrSGAlt_TypeDef

struct	DMA_Init_TypeDef

Typedefs
typedef void(*	DMA_FuncPtr_TypeDef) (unsigned int channel, bool primary, void *user)
	DMA interrupt callback function pointer. More...

Enumerations
enum	DMA_ArbiterConfig_TypeDef { dmaArbitrate1 = _DMA_CTRL_R_POWER_1, dmaArbitrate2 = _DMA_CTRL_R_POWER_2, dmaArbitrate4 = _DMA_CTRL_R_POWER_4, dmaArbitrate8 = _DMA_CTRL_R_POWER_8, dmaArbitrate16 = _DMA_CTRL_R_POWER_16, dmaArbitrate32 = _DMA_CTRL_R_POWER_32, dmaArbitrate64 = _DMA_CTRL_R_POWER_64, dmaArbitrate128 = _DMA_CTRL_R_POWER_128, dmaArbitrate256 = _DMA_CTRL_R_POWER_256, dmaArbitrate512 = _DMA_CTRL_R_POWER_512, dmaArbitrate1024 = _DMA_CTRL_R_POWER_1024 }

enum	DMA_CycleCtrl_TypeDef { dmaCycleCtrlBasic = _DMA_CTRL_CYCLE_CTRL_BASIC, dmaCycleCtrlAuto = _DMA_CTRL_CYCLE_CTRL_AUTO, dmaCycleCtrlPingPong = _DMA_CTRL_CYCLE_CTRL_PINGPONG, dmaCycleCtrlMemScatterGather = _DMA_CTRL_CYCLE_CTRL_MEM_SCATTER_GATHER, dmaCycleCtrlPerScatterGather = _DMA_CTRL_CYCLE_CTRL_PER_SCATTER_GATHER }

enum	DMA_DataInc_TypeDef { dmaDataInc1 = _DMA_CTRL_SRC_INC_BYTE, dmaDataInc2 = _DMA_CTRL_SRC_INC_HALFWORD, dmaDataInc4 = _DMA_CTRL_SRC_INC_WORD, dmaDataIncNone = _DMA_CTRL_SRC_INC_NONE }

enum	DMA_DataSize_TypeDef { dmaDataSize1 = _DMA_CTRL_SRC_SIZE_BYTE, dmaDataSize2 = _DMA_CTRL_SRC_SIZE_HALFWORD, dmaDataSize4 = _DMA_CTRL_SRC_SIZE_WORD }

Functions
void	DMA_ActivateAuto (unsigned int channel, bool primary, void dst, const void src, unsigned int nMinus1)
	Activate DMA auto-request cycle (used for memory-memory transfers). More...

void	DMA_ActivateBasic (unsigned int channel, bool primary, bool useBurst, void dst, const void src, unsigned int nMinus1)
	Activate DMA basic cycle (used for memory-peripheral transfers). More...

void	DMA_ActivatePingPong (unsigned int channel, bool useBurst, void primDst, const void primSrc, unsigned int primNMinus1, void altDst, const void altSrc, unsigned int altNMinus1)
	Activate DMA ping-pong cycle (used for memory-peripheral transfers). More...

void	DMA_ActivateScatterGather (unsigned int channel, bool useBurst, DMA_DESCRIPTOR_TypeDef *altDescr, unsigned int count)
	Activate DMA scatter-gather cycle (used for either memory-peripheral or memory-memory transfers). More...

void	DMA_CfgChannel (unsigned int channel, DMA_CfgChannel_TypeDef *cfg)
	Configure a DMA channel. More...

void	DMA_CfgDescr (unsigned int channel, bool primary, DMA_CfgDescr_TypeDef *cfg)
	Configure DMA descriptor for auto-request, basic or ping-pong DMA cycles. More...

void	DMA_CfgDescrScatterGather (DMA_DESCRIPTOR_TypeDef descr, unsigned int indx, DMA_CfgDescrSGAlt_TypeDef cfg)
	Configure an alternate DMA descriptor for use with scatter-gather DMA cycles. More...

void	DMA_ChannelEnable (unsigned int channel, bool enable)
	Enable or disable a DMA channel. More...

bool	DMA_ChannelEnabled (unsigned int channel)
	Check if DMA channel is enabled. More...

void	DMA_ChannelRequestEnable (unsigned int channel, bool enable)
	Enable or disable a DMA channel request. More...

void	DMA_Init (DMA_Init_TypeDef *init)
	Initializes DMA controller. More...

__STATIC_INLINE void	DMA_IntClear (uint32_t flags)
	Clear one or more pending DMA interrupts. More...

__STATIC_INLINE void	DMA_IntDisable (uint32_t flags)
	Disable one or more DMA interrupts. More...

__STATIC_INLINE void	DMA_IntEnable (uint32_t flags)
	Enable one or more DMA interrupts. More...

__STATIC_INLINE uint32_t	DMA_IntGet (void)
	Get pending DMA interrupt flags. More...

__STATIC_INLINE uint32_t	DMA_IntGetEnabled (void)
	Get enabled and pending DMA interrupt flags. Useful for handling more interrupt sources in the same interrupt handler. More...

__STATIC_INLINE void	DMA_IntSet (uint32_t flags)
	Set one or more pending DMA interrupts. More...

void	DMA_IRQHandler (void)
	Interrupt handler for DMA cycle completion handling. More...

void	DMA_RefreshPingPong (unsigned int channel, bool primary, bool useBurst, void dst, const void src, unsigned int nMinus1, bool stop)
	Refresh a descriptor used in a DMA ping-pong cycle. More...

void	DMA_Reset (void)
	Reset the DMA controller. More...

Typedef Documentation

typedef void(* DMA_FuncPtr_TypeDef) (unsigned int channel, bool primary, void *user)

DMA interrupt callback function pointer.

Parameters:

channel - The DMA channel the callback function is invoked for.
primary - Indicates if callback is invoked for completion of primary (true) or alternate (false) descriptor. This is mainly useful for ping-pong DMA cycles, in order to know which descriptor to refresh.
user - User definable reference that may be used to pass information to be used by the callback handler. If used, the referenced data must be valid at the point when the interrupt handler invokes the callback. If callback changes any data in the provided user structure, remember that those changes are done in interrupt context, and proper protection of data may be required.

Definition at line 135 of file em_dma.h.

Enumeration Type Documentation

enum DMA_ArbiterConfig_TypeDef

Number of transfers before controller does new arbitration.

Enumerator
dmaArbitrate1	Arbitrate after 1 DMA transfer.
dmaArbitrate2	Arbitrate after 2 DMA transfers.
dmaArbitrate4	Arbitrate after 4 DMA transfers.
dmaArbitrate8	Arbitrate after 8 DMA transfers.
dmaArbitrate16	Arbitrate after 16 DMA transfers.
dmaArbitrate32	Arbitrate after 32 DMA transfers.
dmaArbitrate64	Arbitrate after 64 DMA transfers.
dmaArbitrate128	Arbitrate after 128 DMA transfers.
dmaArbitrate256	Arbitrate after 256 DMA transfers.
dmaArbitrate512	Arbitrate after 512 DMA transfers.
dmaArbitrate1024	Arbitrate after 1024 DMA transfers.

Definition at line 99 of file em_dma.h.

enum DMA_CycleCtrl_TypeDef

Type of DMA transfer.

Enumerator
dmaCycleCtrlBasic	Basic DMA cycle.
dmaCycleCtrlAuto	Auto-request DMA cycle.
dmaCycleCtrlPingPong	Ping-pong DMA cycle.
dmaCycleCtrlMemScatterGather	Memory scatter-gather DMA cycle.
dmaCycleCtrlPerScatterGather	Peripheral scatter-gather DMA cycle.

Definition at line 83 of file em_dma.h.

enum DMA_DataInc_TypeDef

Amount source/destination address should be incremented for each data transfer.

Enumerator
dmaDataInc1	Increment address 1 byte.
dmaDataInc2	Increment address 2 bytes.
dmaDataInc4	Increment address 4 bytes.
dmaDataIncNone	Do not increment address.

Definition at line 64 of file em_dma.h.

enum DMA_DataSize_TypeDef

Data sizes (in number of bytes) to be read/written by DMA transfer.

Enumerator
dmaDataSize1	1 byte DMA transfer size.
dmaDataSize2	2 byte DMA transfer size.
dmaDataSize4	4 byte DMA transfer size.

Definition at line 74 of file em_dma.h.

Function Documentation

void DMA_ActivateAuto	(	unsigned int	channel,
		bool	primary,
		void *	dst,
		const void *	src,
		unsigned int	nMinus1
	)

Activate DMA auto-request cycle (used for memory-memory transfers).

Prior to activating the DMA cycle, the channel and descriptor to be used must have been properly configured.

Note: If using this function on a channel already activated and in use by the DMA controller, the behaviour is undefined.

Parameters

[in]	channel	DMA channel to activate DMA cycle for.
[in]	primary	true - activate using primary descriptor false - activate using alternate descriptor
[in]	dst	Address to start location to transfer data to. If NULL, leave setting in descriptor as is from a previous activation.
[in]	src	Address to start location to transfer data from. If NULL, leave setting in descriptor as is from a previous activation.
[in]	nMinus1	Number of DMA transfer elements (minus 1) to transfer (<= 1023). The size of the DMA transfer element (1, 2 or 4 bytes) is configured with DMA_CfgDescr().

Definition at line 386 of file em_dma.c.

References _DMA_CTRL_N_MINUS_1_MASK, _DMA_CTRL_N_MINUS_1_SHIFT, DMA, DMA_CHAN_COUNT, and dmaCycleCtrlAuto.

void DMA_ActivateBasic	(	unsigned int	channel,
		bool	primary,
		bool	useBurst,
		void *	dst,
		const void *	src,
		unsigned int	nMinus1
	)

Activate DMA basic cycle (used for memory-peripheral transfers).

Prior to activating the DMA cycle, the channel and descriptor to be used must have been properly configured.

Note: If using this function on a channel already activated and in use by the DMA controller, the behaviour is undefined.

Parameters

[in]	channel	DMA channel to activate DMA cycle for.
[in]	primary	true - activate using primary descriptor false - activate using alternate descriptor
[in]	useBurst	The burst feature is only used on peripherals supporting DMA bursts. Bursts must not be used if the total length (as given by nMinus1) is less than the arbitration rate configured for the descriptor. Please refer to the reference manual for further details on burst usage.
[in]	dst	Address to start location to transfer data to. If NULL, leave setting in descriptor as is from a previous activation.
[in]	src	Address to start location to transfer data from. If NULL, leave setting in descriptor as is from a previous activation.
[in]	nMinus1	Number of DMA transfer elements (minus 1) to transfer (<= 1023). The size of the DMA transfer element (1, 2 or 4 bytes) is configured with DMA_CfgDescr().

Definition at line 449 of file em_dma.c.

References _DMA_CTRL_N_MINUS_1_MASK, _DMA_CTRL_N_MINUS_1_SHIFT, DMA, DMA_CHAN_COUNT, and dmaCycleCtrlBasic.

Referenced by CDC_StateChangeEvent().

void DMA_ActivatePingPong	(	unsigned int	channel,
		bool	useBurst,
		void *	primDst,
		const void *	primSrc,
		unsigned int	primNMinus1,
		void *	altDst,
		const void *	altSrc,
		unsigned int	altNMinus1
	)

Activate DMA ping-pong cycle (used for memory-peripheral transfers).

Prior to activating the DMA cycle, the channel and both descriptors must have been properly configured. The primary descriptor is always the first descriptor to be used by the DMA controller.

Note: If using this function on a channel already activated and in use by the DMA controller, the behaviour is undefined.

Parameters

[in]	channel	DMA channel to activate DMA cycle for.
[in]	useBurst	The burst feature is only used on peripherals supporting DMA bursts. Bursts must not be used if the total length (as given by nMinus1) is less than the arbitration rate configured for the descriptors. Please refer to the reference manual for further details on burst usage. Notice that this setting is used for both the primary and alternate descriptors.
[in]	primDst	Address to start location to transfer data to, for primary descriptor. If NULL, leave setting in descriptor as is from a previous activation.
[in]	primSrc	Address to start location to transfer data from, for primary descriptor. If NULL, leave setting in descriptor as is from a previous activation.
[in]	primNMinus1	Number of DMA transfer elements (minus 1) to transfer (<= 1023), for primary descriptor. The size of the DMA transfer element (1, 2 or 4 bytes) is configured with DMA_CfgDescr().
[in]	altDst	Address to start location to transfer data to, for alternate descriptor. If NULL, leave setting in descriptor as is from a previous activation.
[in]	altSrc	Address to start location to transfer data from, for alternate descriptor. If NULL, leave setting in descriptor as is from a previous activation.
[in]	altNMinus1	Number of DMA transfer elements (minus 1) to transfer (<= 1023), for alternate descriptor. The size of the DMA transfer element (1, 2 or 4 bytes) is configured with DMA_CfgDescr().

Definition at line 521 of file em_dma.c.

References _DMA_CTRL_N_MINUS_1_MASK, _DMA_CTRL_N_MINUS_1_SHIFT, DMA, DMA_CHAN_COUNT, and dmaCycleCtrlPingPong.

void DMA_ActivateScatterGather	(	unsigned int	channel,
		bool	useBurst,
		DMA_DESCRIPTOR_TypeDef *	altDescr,
		unsigned int	count
	)

Activate DMA scatter-gather cycle (used for either memory-peripheral or memory-memory transfers).

Prior to activating the DMA cycle, the array with alternate descriptors must have been properly configured. This function can be reused without reconfiguring the alternate descriptors, as long as count is the same.

Note: If using this function on a channel already activated and in use by the DMA controller, the behaviour is undefined.

Parameters

[in]	channel	DMA channel to activate DMA cycle for.
[in]	useBurst	The burst feature is only used on peripherals supporting DMA bursts (and thus this parameter is ignored for memory scatter-gather cycles). This parameter determines if bursts should be enabled during DMA transfers using the alternate descriptors. Bursts must not be used if the total length (as given by nMinus1 for the alternate descriptor) is less than the arbitration rate configured for the descriptor. Please refer to the reference manual for further details on burst usage.
[in,out]	altDescr	Pointer to start of array with prepared alternate descriptors. The last descriptor will have its cycle control type reprogrammed to basic type.
[in]	count	Number of alternate descriptors in `altDescr` array. Maximum number of alternate descriptors is 256.

Definition at line 591 of file em_dma.c.

References _DMA_CTRL_CYCLE_CTRL_MASK, _DMA_CTRL_CYCLE_CTRL_SHIFT, _DMA_CTRL_DST_INC_SHIFT, _DMA_CTRL_DST_SIZE_SHIFT, _DMA_CTRL_N_MINUS_1_SHIFT, _DMA_CTRL_NEXT_USEBURST_SHIFT, _DMA_CTRL_R_POWER_SHIFT, _DMA_CTRL_SRC_INC_SHIFT, _DMA_CTRL_SRC_PROT_CTRL_MASK, _DMA_CTRL_SRC_SIZE_SHIFT, DMA_DESCRIPTOR_TypeDef::CTRL, DMA, DMA_CHAN_COUNT, dmaArbitrate4, dmaCycleCtrlAuto, dmaCycleCtrlBasic, dmaCycleCtrlMemScatterGather, dmaCycleCtrlPerScatterGather, dmaDataInc4, dmaDataSize4, DMA_DESCRIPTOR_TypeDef::DSTEND, DMA_CB_TypeDef::primary, DMA_DESCRIPTOR_TypeDef::SRCEND, and DMA_DESCRIPTOR_TypeDef::USER.

void DMA_CfgChannel	(	unsigned int	channel,
		DMA_CfgChannel_TypeDef *	cfg
	)

Configure a DMA channel.

Configure miscellaneous issues for a DMA channel. This function is typically used once to setup a channel for a certain type of use.

Note: If using this function on a channel already in use by the DMA controller, the behaviour is undefined.

Parameters

[in]	channel	DMA channel to configure.
[in]	cfg	Configuration to use.

Definition at line 701 of file em_dma.c.

References BUS_RegBitWrite(), DMA_CfgChannel_TypeDef::cb, DMA, DMA_CHAN_COUNT, DMA_CfgChannel_TypeDef::enableInt, DMA_CfgChannel_TypeDef::highPri, DMA_CfgChannel_TypeDef::select, and DMA_DESCRIPTOR_TypeDef::USER.

Referenced by NANDFLASH_Init().

void DMA_CfgDescr	(	unsigned int	channel,
		bool	primary,
		DMA_CfgDescr_TypeDef *	cfg
	)

Configure DMA descriptor for auto-request, basic or ping-pong DMA cycles.

This function is used for configuration of a descriptor for the following DMA cycle types:

auto-request - used for memory/memory transfer
basic - used for a peripheral/memory transfer
ping-pong - used for a ping-pong based peripheral/memory transfer style providing time to refresh one descriptor while the other is in use.

The DMA cycle is not activated, please see DMA_ActivateAuto(), DMA_ActivateBasic() or DMA_ActivatePingPong() to activate the DMA cycle. In many cases, the configuration only has to be done once, and all subsequent cycles may be activated with the activate function.

For ping-pong DMA cycles, this function must be used both on the primary and the alternate descriptor prior to activating the DMA cycle.

Notice that the DMA channel must also be configured, see DMA_CfgChannel().

Note: If using this function on a descriptor already activated and in use by the DMA controller, the behaviour is undefined.

Parameters

[in]	channel	DMA channel to configure for.
[in]	primary	true - configure primary descriptor false - configure alternate descriptor
[in]	cfg	Configuration to use.

Definition at line 776 of file em_dma.c.

References _DMA_CTRL_DST_INC_SHIFT, _DMA_CTRL_DST_SIZE_SHIFT, _DMA_CTRL_N_MINUS_1_SHIFT, _DMA_CTRL_NEXT_USEBURST_SHIFT, _DMA_CTRL_R_POWER_SHIFT, _DMA_CTRL_SRC_INC_SHIFT, _DMA_CTRL_SRC_PROT_CTRL_SHIFT, _DMA_CTRL_SRC_SIZE_SHIFT, DMA_CfgDescr_TypeDef::arbRate, DMA_DESCRIPTOR_TypeDef::CTRL, DMA, DMA_CHAN_COUNT, DMA_CTRL_CYCLE_CTRL_INVALID, DMA_CfgDescr_TypeDef::dstInc, DMA_CfgDescr_TypeDef::hprot, DMA_CfgDescr_TypeDef::size, and DMA_CfgDescr_TypeDef::srcInc.

void DMA_CfgDescrScatterGather	(	DMA_DESCRIPTOR_TypeDef *	descr,
		unsigned int	indx,
		DMA_CfgDescrSGAlt_TypeDef *	cfg
	)

Configure an alternate DMA descriptor for use with scatter-gather DMA cycles.

In scatter-gather mode, the alternate descriptors are located in one contiguous memory area. Each of the alternate descriptor must be fully configured prior to starting the scatter-gather DMA cycle.

The DMA cycle is not activated by this function, please see DMA_ActivateScatterGather() to activate the DMA cycle. In some cases, the alternate configuration only has to be done once, and all subsequent transfers may be activated with the activate function.

Notice that the DMA channel must also be configured, see DMA_CfgChannel().

Parameters

[in]	descr	Points to start of memory area holding the alternate descriptors.
[in]	indx	Alternate descriptor index number to configure (numbered from 0).
[in]	cfg	Configuration to use.

Definition at line 898 of file em_dma.c.

void DMA_ChannelEnable	(	unsigned int	channel,
		bool	enable
	)

Enable or disable a DMA channel.

Use this function to explicitly enable or disable a DMA channel. A DMA channel is automatically disabled when the DMA controller has finished a transaction.

Parameters

[in]	channel	DMA channel to enable or disable.
[in]	enable	If 'true' the channel will be enabled. If 'false' the channel will be disabled.

Definition at line 974 of file em_dma.c.

References DMA, and DMA_CHAN_COUNT.

Referenced by DMADRV_StopTransfer().

bool DMA_ChannelEnabled ( unsigned int channel )

Check if DMA channel is enabled.

The DMA channel is disabled when the DMA controller has finished a DMA cycle.

Parameters

[in] channel DMA channel to check.

Returns: true if channel is enabled, false if not.

Definition at line 1003 of file em_dma.c.

References DMA, and DMA_CHAN_COUNT.

Referenced by DMADRV_TransferActive().

void DMA_ChannelRequestEnable	(	unsigned int	channel,
		bool	enable
	)

Enable or disable a DMA channel request.

Use this function to enable or disable a DMA channel request. This will prevent the DMA from proceeding after its current transaction if disabled.

Parameters

[in]	channel	DMA channel to enable or disable request on.
[in]	enable	If 'true' request will be enabled. If 'false' request will be disabled.

Definition at line 1025 of file em_dma.c.

References BUS_RegBitWrite(), DMA, and DMA_CHAN_COUNT.

Referenced by DMADRV_PauseTransfer(), and DMADRV_ResumeTransfer().

void DMA_Init ( DMA_Init_TypeDef * init )

Initializes DMA controller.

This function will reset and prepare the DMA controller for use. Although it may be used several times, it is normally only used during system init. If reused during normal operation, notice that any ongoing DMA transfers will be aborted. When completed, the DMA controller is in an enabled state.

Note: Must be invoked before using the DMA controller.

Parameters

[in] init Pointer to a structure containing DMA init information.

Definition at line 1057 of file em_dma.c.

References _DMA_CONFIG_CHPROT_SHIFT, CMU_ClockEnable(), cmuClock_DMA, DMA_Init_TypeDef::controlBlock, DMA, DMA_CONFIG_EN, DMA_IEN_ERR, DMA_IRQn, DMA_Reset(), and DMA_Init_TypeDef::hprot.

Referenced by DMADRV_Init(), and NANDFLASH_Init().

__STATIC_INLINE void DMA_IntClear ( uint32_t flags )

Clear one or more pending DMA interrupts.

Parameters

[in] flags Pending DMA interrupt sources to clear. Use one or more valid interrupt flags for the DMA module (DMA_IFC_nnn).

Definition at line 462 of file em_dma.h.

References DMA.

__STATIC_INLINE void DMA_IntDisable ( uint32_t flags )

Disable one or more DMA interrupts.

Parameters

[in] flags DMA interrupt sources to disable. Use one or more valid interrupt flags for the DMA module (DMA_IEN_nnn).

Definition at line 476 of file em_dma.h.

References DMA.

__STATIC_INLINE void DMA_IntEnable ( uint32_t flags )

Enable one or more DMA interrupts.

Note: Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. Consider using DMA_IntClear() prior to enabling if such a pending interrupt should be ignored.

Parameters

[in] flags DMA interrupt sources to enable. Use one or more valid interrupt flags for the DMA module (DMA_IEN_nnn).

Definition at line 495 of file em_dma.h.

References DMA.

__STATIC_INLINE uint32_t DMA_IntGet ( void )

Get pending DMA interrupt flags.

Note: The event bits are not cleared by the use of this function.

Returns: DMA interrupt sources pending. Returns one or more valid interrupt flags for the DMA module (DMA_IF_nnn).

Definition at line 512 of file em_dma.h.

References DMA.

__STATIC_INLINE uint32_t DMA_IntGetEnabled ( void )

Get enabled and pending DMA interrupt flags. Useful for handling more interrupt sources in the same interrupt handler.

Note: Interrupt flags are not cleared by the use of this function.

Returns

Pending and enabled DMA interrupt sources The return value is the bitwise AND of

the enabled interrupt sources in DMA_IEN and
the pending interrupt flags DMA_IF

Definition at line 532 of file em_dma.h.

References DMA.

__STATIC_INLINE void DMA_IntSet ( uint32_t flags )

Set one or more pending DMA interrupts.

Parameters

[in] flags DMA interrupt sources to set to pending. Use one or more valid interrupt flags for the DMA module (DMA_IFS_nnn).

Definition at line 549 of file em_dma.h.

References DMA.

void DMA_IRQHandler ( void )

Interrupt handler for DMA cycle completion handling.

Clears any pending flags and calls registered callback (if any).

If using the default interrupt vector table setup provided, this function is automatically placed in the IRQ table due to weak linking. If taking control over the interrupt vector table in some other way, this interrupt handler must be installed in order to be able to support callback actions.

In order for the user to implement a custom IRQ handler or run without a DMA IRQ handler, the user can define EXCLUDE_DEFAULT_DMA_IRQ_HANDLER with a #define statement or with the compiler option -D.

Definition at line 284 of file em_dma.c.

References DMA_CB_TypeDef::cbFunc, DMA, DMA_IF_ERR, DMA_CB_TypeDef::primary, and DMA_CB_TypeDef::userPtr.

void DMA_RefreshPingPong	(	unsigned int	channel,
		bool	primary,
		bool	useBurst,
		void *	dst,
		const void *	src,
		unsigned int	nMinus1,
		bool	stop
	)

Refresh a descriptor used in a DMA ping-pong cycle.

During a ping-pong DMA cycle, the DMA controller automatically alternates between primary and alternate descriptors, when completing use of a descriptor. While the other descriptor is in use by the DMA controller, the SW should refresh the completed descriptor. This is typically done from the callback defined for the ping-pong cycle.

Parameters

[in]	channel	DMA channel to refresh ping-pong descriptor for.
[in]	primary	true - refresh primary descriptor false - refresh alternate descriptor
[in]	useBurst	The burst feature is only used on peripherals supporting DMA bursts. Bursts must not be used if the total length (as given by nMinus1) is less than the arbitration rate configured for the descriptor. Please refer to the reference manual for further details on burst usage.
[in]	dst	Address to start location to transfer data to. If NULL, leave setting in descriptor as is.
[in]	src	Address to start location to transfer data from. If NULL, leave setting in descriptor as is.
[in]	nMinus1	Number of DMA transfer elements (minus 1) to transfer (<= 1023). The size of the DMA transfer element (1, 2 or 4 bytes) is configured with DMA_CfgDescr().
[in]	stop	Indicate that the DMA ping-pong cycle shall stop after completing use of this descriptor.

Definition at line 1135 of file em_dma.c.

References _DMA_CTRL_CYCLE_CTRL_MASK, _DMA_CTRL_CYCLE_CTRL_SHIFT, _DMA_CTRL_DST_INC_MASK, _DMA_CTRL_DST_INC_NONE, _DMA_CTRL_DST_INC_SHIFT, _DMA_CTRL_N_MINUS_1_MASK, _DMA_CTRL_N_MINUS_1_SHIFT, _DMA_CTRL_SRC_INC_MASK, _DMA_CTRL_SRC_INC_NONE, _DMA_CTRL_SRC_INC_SHIFT, DMA_DESCRIPTOR_TypeDef::CTRL, DMA, DMA_CHAN_COUNT, dmaCycleCtrlBasic, dmaCycleCtrlPingPong, DMA_DESCRIPTOR_TypeDef::DSTEND, and DMA_DESCRIPTOR_TypeDef::SRCEND.

void DMA_Reset ( void )

Reset the DMA controller.

This functions will disable the DMA controller and set it to a reset state.

Note: Notice that any ongoing transfers will be aborted.

Definition at line 1227 of file em_dma.c.

References _DMA_CH_CTRL_RESETVALUE, _DMA_CHALTC_MASK, _DMA_CHENC_MASK, _DMA_CHPRIC_MASK, _DMA_CHREQMASKC_MASK, _DMA_CHUSEBURSTC_MASK, _DMA_CONFIG_RESETVALUE, _DMA_IEN_RESETVALUE, _DMA_IFC_MASK, DMA, DMA_CHAN_COUNT, DMA_ERRORC_ERRORC, and DMA_IRQn.

Referenced by DMA_Init().

Detailed Description

Data Structures

Typedefs

Enumerations

Functions

Typedef Documentation

Enumeration Type Documentation

Function Documentation