Direct Memory Access#

sl_dma_transfer_type_t#

sl_dma_transfer_type_t

Enumeration holds transfer types of DMA.

sl_dma_transfer_mode_t#

sl_dma_transfer_mode_t

Enumeration holds transfer modes of DMA.

sl_dma_peripheral_ack_t#

sl_dma_peripheral_ack_t

Enumeration holds peripheral ACK signals to DMA.

sl_dma_transfer_size_t#

sl_dma_transfer_size_t

Enumeration holds DMA transfer sizes.

sl_dma_transfer_inc_t#

sl_dma_transfer_inc_t

Enumeration holds DMA transfer address increment for source and destination.

sl_dma_callback_code_t#

sl_dma_callback_code_t

Enumeration holds 8-bit codes which are used by callback_type in sl_si91x_dma_unregister_callbacks function.

sl_dma_transfer_complete#

typedef void(* sl_dma_transfer_complete) (uint32_t channel, void *data) )(uint32_t channel, void *data)

Typedef for user-supplied callback function which is called when a DMA transfer completes.

sl_dma_error#

typedef void(* sl_dma_error) (uint32_t channel, void *data) )(uint32_t channel, void *data)

Typedef for user-supplied callback function which is called when a DMA error occurs.

sl_channel_allocation_data_t#

sl_channel_data_t sl_channel_allocation_data_t[2][SL_CHANNEL_COUNT]

DMA driver channel allocator.

sl_si91x_dma_init#

sl_status_t sl_si91x_dma_init (sl_dma_init_t * dma_init)

This API initializes the DMA peripheral.

This API enables DMA clock and clears DMA interrupts. Configure dma_init->dma_number to 0 for initializing UDMA0 and 1 for initializing UDMA1

• Pre-condition:

  • none

Returns

• Initialization status

  • SL_STATUS_OK - Initialization success

  • SL_STATUS_NOT_INITIALIZED - Initialization fail

sl_si91x_dma_deinit#

sl_status_t sl_si91x_dma_deinit (uint32_t dma_number)

This function de-initializes the DMA peripheral.

This API disables the DMA peripheral clock and interrupts. DMA will be deinitialized only if there is no ongoing transfer.

• Pre-condition:

  • sl_si91x_dma_init

Returns

• deinitialization status

  • SL_STATUS_OK - Deinit success

  • SL_STATUS_BUSY - Cannot deinit the peripheral due to an ongoing transfer

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

sl_si91x_dma_allocate_channel#

sl_status_t sl_si91x_dma_allocate_channel (uint32_t dma_number, uint32_t * channel_no, uint32_t priority)

This API allocates DMA channel for the transfer.

This API checks the available DMA channel and allocates the channel. This function also sets the priority of the allocated channel and assigns the channel number to the *channel_no variable. If no channel is available, it will return SL_DMA_NO_CHANNEL_AVAILABLE. Note: Users can also initialize the desired channel number and this API checks whether the desired channel is available and allocates the channel if available. If users want the driver to allocate the available channel, channel_no should be initialized to 0.

• Pre-condition:

  • sl_si91x_dma_init

Returns

• channel allocation status:

  • SL_STATUS_OK - Channel allocated

  • SL_STATUS_DMA_NO_CHANNEL_AVAILABLE - All DMA channels are allocated

  • SL_STATUS_DMA_CHANNEL_ALLOCATED - The desired channel is already allocated

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

  • SL_STATUS_INVALID_PARAMETER - Channel no is invalid

sl_si91x_dma_deallocate_channel#

sl_status_t sl_si91x_dma_deallocate_channel (uint32_t dma_number, uint32_t channel_no)

This API deallocates the DMA channel.

This API deallocates the DMA channel if there is no ongoing transfer on the channel. Deallocating the channel will also unregister the callbacks for transfer complete and error.

• Pre-conditions:

  • sl_si91x_dma_init

  • sl_si91x_dma_allocate_channel

Returns

• channel deallocation status:

  • SL_STATUS_OK - Channel deallocated

  • SL_STATUS_BUSY - Cannot deallocate channel due to an ongoing transfer

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

  • SL_STATUS_INVALID_PARAMETER - Channel no is invalid

sl_si91x_dma_register_callbacks#

sl_status_t sl_si91x_dma_register_callbacks (uint32_t dma_number, uint32_t channel_no, sl_dma_callback_t * callback_t)

This API registers the DMA callbacks (transfer complete & error).

User must update the sl_dma_callback_t structure and pass its address to this function. A separate callback can be present for transfer complete and error for each channel.

• Pre-conditions:

  • sl_si91x_dma_init

  • sl_si91x_dma_allocate_channel

Returns

• channel deallocation status:

  • SL_STATUS_OK - Callback registered successfully

  • SL_STATUS_INVALID_PARAMETER - Invalid channel number

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

sl_si91x_dma_unregister_callbacks#

sl_status_t sl_si91x_dma_unregister_callbacks (uint32_t dma_number, uint32_t channel_no, uint8_t callback_type)

This API unregisters the DMA callbacks (transfer complete & error).

Users need to update the 8-bit variable callback_type and pass to the function Each bit is mapped to a specific callback.

• Pre-conditions:

  • sl_si91x_dma_init

  • sl_si91x_dma_allocate_channel

  • sl_si91x_dma_register_callbacks

Returns

• channel de-allocation status:

  • SL_STATUS_OK - Callback unregistered successfully

  • SL_STATUS_INVALID_PARAMETER - Invalid channel number

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

sl_si91x_dma_transfer#

sl_status_t sl_si91x_dma_transfer (uint32_t dma_number, uint32_t channel_no, sl_dma_xfer_t * dma_transfer_t)

This API starts the DMA transfer.

This API configures the DMA channel descriptor and initiates the DMA transfer DMA primary descriptor is updated in this function and based on transfer mode alternate descriptor is updated (only for ping pong mode). Also other DMA parameters like peripheral ACK signal (for peripheral memory transfers), DMA priority, etc. are updated in this function.

• Pre-conditions:

  • sl_si91x_dma_init

  • sl_si91x_dma_allocate_channel

  • sl_si91x_dma_register_callbacks

Returns

• DMA transfer status:

  • SL_STATUS_OK - Transfer started successfully

  • SL_STATUS_SUSPENDED - Transfer initialization fails

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

  • SL_STATUS_INVALID_PARAMETER - Channel no is invalid

sl_si91x_dma_simple_transfer#

sl_status_t sl_si91x_dma_simple_transfer (uint32_t dma_number, uint32_t channel_no, void * src_addr, void * dst_addr, uint32_t data_size)

This API starts a simple memory to memory DMA transfer.

This API configures the DMA channel descriptor and initiates simple memory-to-memory DMA transfer. Users need to pass the source address and destination address of the transfer along with transfer length in bytes.

• Pre-conditions:

  • sl_si91x_dma_init

  • sl_si91x_dma_allocate_channel

  • sl_si91x_dma_register_callbacks

Returns

• DMA transfer status:

  • SL_STATUS_OK - Transfer success

  • SL_STATUS_SUSPENDED - Transfer initialization fails

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

  • SL_STATUS_INVALID_PARAMETER - Channel no is invalid

sl_si91x_dma_stop_transfer#

sl_status_t sl_si91x_dma_stop_transfer (uint32_t dma_number, uint32_t channel_no)

This API stops DMA transfer.

This API stops any active transfer on the channel by disabling the DMA channel. If there is no active transfer on the channel, this function returns SL_DMA_CHANNEL_IDLE

• Pre-conditions:

  • sl_si91x_dma_init

  • sl_si91x_dma_allocate_channel

  • sl_si91x_dma_simple_transfer/sl_si91x_dma_transfer

Returns

• DMA transfer status:

  • SL_STATUS_OK - Transfer stopped successfully

  • SL_STATUS_IDLE - There is no active transfer on the channel

  • SL_STATUS_INVALID_PARAMETER - Invalid channel number

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

sl_si91x_dma_channel_status_get#

sl_status_t sl_si91x_dma_channel_status_get (uint32_t dma_number, uint32_t channel_no)

This API returns the DMA channel status.

This API returns the following channel status, SL_STATUS_DMA_CHANNEL_ALREADY_ALLOCATED - DMA channel allocated but no active transfer in progress SL_STATUS_BUSY - Channel is allocated and active transfer is in progress SL_STATUS_IDLE - Channel is not allocated.

• Pre-conditions:

  • sl_si91x_dma_init

Returns

• channel status

  • SL_STATUS_IDLE - Channel is not allocated

  • SL_STATUS_DMA_CHANNEL_ALREADY_ALLOCATED - Channel is already allocated and idle

  • SL_STATUS_BUSY - Channel is allocated and busy

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

  • SL_STATUS_INVALID_PARAMETER - Channel no is invalid

sl_si91x_dma_channel_enable#

sl_status_t sl_si91x_dma_channel_enable (uint32_t dma_number, uint32_t channel_no)

This API enables the DMA channel.

Enabling channel will trigger DMA transfer if DMA is already enabled. Also, the channel should be allocated and transfer parameters should be configured before enabling the channel.

• Pre-conditions:

  • sl_si91x_dma_init

Returns

• channel status

  • SL_STATUS_OK - Channel enables success

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

  • SL_STATUS_INVALID_PARAMETER - Channel no is invalid

sl_si91x_dma_channel_disable#

sl_status_t sl_si91x_dma_channel_disable (uint32_t dma_number, uint32_t channel_no)

This API disables the DMA channel.

Disabling the DMA channel will abort any ongoing active transfers on the channel. Enabling the channel back will not resume the previous transfer.

• Pre-condition:

  • sl_si91x_dma_init

Returns

• channel status

  • SL_STATUS_OK - Channel disable success

  • SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

  • SL_STATUS_INVALID_PARAMETER - Channel no is invalid

sl_si91x_dma_enable#

sl_status_t sl_si91x_dma_enable (uint32_t dma_number)

This API enables DMA peripheral.

Enabling the DMA will trigger transfer if the channel is already enabled. Also, the channel should be allocated and transfer parameters should be configured before enabling the DMA.

• Pre-condition:

  • sl_si91x_dma_init

Returns

• SL_STATUS_OK - Channel enable success SL_STATUS_NOT_INITIALIZED - DMA peripheral not initialized

SL_STATUS_DMA_CHANNEL_ALLOCATED#

#define SL_STATUS_DMA_CHANNEL_ALLOCATED

  (sl_status_t)0x45

SL_STATUS_DMA_NO_CHANNEL_AVAILABLE#

#define SL_STATUS_DMA_NO_CHANNEL_AVAILABLE

  (sl_status_t)0x46

SL_STATUS_DMA_CHANNEL_ALREADY_UNALLOCATED#

#define SL_STATUS_DMA_CHANNEL_ALREADY_UNALLOCATED

  (sl_status_t)0X47

SL_STATUS_DMA_CHANNEL_UNALLOCATED#

#define SL_STATUS_DMA_CHANNEL_UNALLOCATED

  (sl_status_t)0X48

SL_CHANNEL_COUNT#

#define SL_CHANNEL_COUNT

32

ALTERNATE_DESCRIPTOR_DISABLE#

#define ALTERNATE_DESCRIPTOR_DISABLE

0

ALTERNATE_DESCRIPTOR_ENABLE#

#define ALTERNATE_DESCRIPTOR_ENABLE

1

BURST_REQUEST_ENABLE#

#define BURST_REQUEST_ENABLE

1

BURST_REQUEST_DISABLE#

#define BURST_REQUEST_DISABLE

0

CHANNEL_PRIO_DISABLE#

#define CHANNEL_PRIO_DISABLE

0

CHANNEL_PRIO_ENABLE#

#define CHANNEL_PRIO_ENABLE

1

PERIPHERAL_ACK_DISABLE#

#define PERIPHERAL_ACK_DISABLE

0

PERIPHERAL_REQUEST_DISABLE#

#define PERIPHERAL_REQUEST_DISABLE

0

PERIPHERAL_REQUEST_ENABLE#

#define PERIPHERAL_REQUEST_ENABLE

1

REQUEST_MASK_DISABLE#

#define REQUEST_MASK_DISABLE

0

NEXT_BURST_ENABLE#

#define NEXT_BURST_ENABLE

NEXT_BURST_DISABLE#

#define NEXT_BURST_DISABLE

0

SOURCE_PROTECT_CONTROL_DISABLE#

#define SOURCE_PROTECT_CONTROL_DISABLE

0x000

DESTINATION_PROTECT_CONTROL_DISABLE#

#define DESTINATION_PROTECT_CONTROL_DISABLE

0x000