DMA Manager

Overview

DMA Manager provides a series of functions to manage the DMAMUX channels.

Function groups

DMAMGR Initialization and De-initialization

This function group initializes and deinitializes the DMA Manager.

DMAMGR Operation

This function group requests/releases the DMAMUX channel and configures the channel request source.

Typical use case

DMAMGR static channel allocate

DMAMUX_Type *dmamux_base;
uint8_t channel;

/* Initialize DMAMGR */
DMAMGR_Init();
/* Request a DMAMUX channel by static allocate mechanism */
dmamux_base = DMAMUX0;
channel = 0;
DMAMGR_RequestChannel(kDmaRequestMux0AlwaysOn63, &dmamux_base, &channel, kDMAMGR_STATIC_ALLOCATE);

DMAMGR dynamic channel allocate

DMAMUX_Type *dmamux_base;
uint8_t channel;

/* Initialize DMAMGR */
DMAMGR_Init();
/* Request a DMAMUX channel by static allocate mechanism */
dmamux_base = DMAMUX0;
channel = 0;
DMAMGR_RequestChannel(kDmaRequestMux0AlwaysOn63, &dmamux_base, &channel, kDMAMGR_DYNAMIC_ALLOCATE);

Macros
#define	DMAMGR_DYNAMIC_ALLOCATE   0xFFU
	Dynamic channel allocate mechanism. More...

Enumerations
enum	_dma_manager_status {   kStatus_DMAMGR_ChannelOccupied = MAKE_STATUS(kStatusGroup_DMAMGR, 0),   kStatus_DMAMGR_ChannelNotUsed = MAKE_STATUS(kStatusGroup_DMAMGR, 1),   kStatus_DMAMGR_NoFreeChannel = MAKE_STATUS(kStatusGroup_DMAMGR, 2),   kStatus_DMAMGR_ChannelNotMatchSource = MAKE_STATUS(kStatusGroup_DMAMGR, 3) }
	DMA manager status. More...

DMAMGR Initialize and De-initialize
void	DMAMGR_Init (void)
	Initializes the DAM manager. More...
void	DMAMGR_Deinit (void)
	Deinitializes the DMA manager. More...

DMAMGR Operation
status_t	DMAMGR_RequestChannel (dma_request_source_t requestSource, uint8_t virtualChannel, void *handle)
	Requests a DMA channel. More...
status_t	DMAMGR_ReleaseChannel (void *handle)
	Releases a DMA channel. More...

Macro Definition Documentation

#define DMAMGR_DYNAMIC_ALLOCATE   0xFFU

Enumeration Type Documentation

enum _dma_manager_status

Enumerator
kStatus_DMAMGR_ChannelOccupied	Channel has been occupied.
kStatus_DMAMGR_ChannelNotUsed	Channel has not been used.
kStatus_DMAMGR_NoFreeChannel	All channel has been occupied.
kStatus_DMAMGR_ChannelNotMatchSource	Channel do not match the request source.

Function Documentation

void DMAMGR_Init

(

void

)

This function initializes the DMA manager, ungates all DMAMUX clocks, and initializes the eDMA or DMA peripheral.

void DMAMGR_Deinit

(

void

)

This function deinitializes the DMA manager, disables all DMAMUX channel, gates all DMAMUX clock, and deinitializes the eDMA or DMA peripheral.

status_t DMAMGR_RequestChannel	(	dma_request_source_t	requestSource,
		uint8_t	virtualChannel,
		void *	handle
	)

This function request a DMA channel which is not occupied. There are two channels to allocate the mechanism dynamic and static. For the dynamic allocation mechanism (virtualChannel = DMAMGR_DYNAMIC_ALLOCATE), DMAMGR allocates a DMA channel according to the given request source and then configure it. For static allocation mechanism, DMAMGR configures the given channel according to the given request source and channel number.

Parameters

requestSource	DMA channel request source number. See the soc.h.
virtualChannel	The channel number user wants to occupy. If using the dynamic channel allocate mechanism, set the virtualChannel equal to DMAMGR_DYNAMIC_ALLOCATE.
handle	DMA or eDMA handle pointer.

Return values

kStatus_Success	In dynamic/static channel allocate mechanism, allocate DMAMUX channel successfully.
kStatus_DMAMGR_NoFreeChannel	In dynamic channel allocate mechanism, all DMAMUX channels has been occupied.
kStatus_DMAMGR_ChannelNotMatchSource	In static channel allocate mechanism, the given channel do not match the given request.
kStatus_DMAMGR_ChannelOccupied	In static channel allocate mechanism, the given channel has been occupied.

status_t DMAMGR_ReleaseChannel

(

void *

handle

)

This function releases an occupied DMA channel.

Parameters

handle

DMA or eDMA handle pointer.

Return values

kStatus_Success	Release the given channel successfully.
kStatus_DMAMGR_ChannelNotUsed	The given channel which to be released is not been used before.