Direct Memory Access#

sl_dma_transfer_type_t#

sl_dma_transfer_type_t

Enumeration to represent DMA transfer types.

This enumeration defines the different types of DMA transfers that can be performed.

sl_dma_transfer_mode_t#

sl_dma_transfer_mode_t

Enumeration to represent DMA transfer modes.

This enumeration defines the different transfer modes available for DMA operations.

sl_dma_peripheral_ack_t#

sl_dma_peripheral_ack_t

Enumeration that holds peripheral ACK signals for DMA.

This enumeration defines the ACK codes for various peripherals that can be used with DMA.

sl_dma_transfer_size_t#

sl_dma_transfer_size_t

Enumeration that holds DMA transfer sizes.

This enumeration defines the different transfer sizes available for DMA operations.

sl_dma_transfer_inc_t#

sl_dma_transfer_inc_t

Enumeration that holds DMA transfer address increment options for source and destination.

This enumeration defines the different address increment options available for DMA transfers, specifying how the source and destination addresses should be incremented after each transfer.

sl_dma_callback_code_t#

sl_dma_callback_code_t

Enumeration that holds 8-bit codes used by the callback_type parameter in the sl_si91x_dma_unregister_callbacks function.

This enumeration defines the 8-bit codes for different types of DMA callbacks that can be unregistered.

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.

This typedef defines the callback function type that is used by the DMA driver to notify the application when a DMA transfer has completed.

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.

This typedef defines the callback function type that is used by the DMA driver to notify the application when a DMA error has occurred.

sl_dma0_channel_allocation_data_t#

sl_channel_data_t sl_dma0_channel_allocation_data_t[SL_DMA0_CHANNEL_COUNT]

DMA0 channel allocation data.

This external variable holds the allocation data for all channels of DMA0, including priority, allocation status, callback functions, transfer type, and transfer mode. DMA0 channel allocator

sl_ulp_dma_channel_allocation_data_t#

sl_channel_data_t sl_ulp_dma_channel_allocation_data_t[SL_ULP_DMA_CHANNEL_COUNT]

ULP_DMA channel allocation data.

This external variable holds the allocation data for all channels of ULP_DMA, including priority, allocation status, callback functions, transfer type, and transfer mode. ULP_DMA channel allocator

sl_si91x_dma_init#

sl_status_t sl_si91x_dma_init (sl_dma_init_t * dma_init)

To initialize the DMA peripheral.

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

Returns

• sl_status_t Initialization status:

  • SL_STATUS_OK (0x0000) - Initialization success.

  • SL_STATUS_NOT_INITIALIZED (0x0001) - Initialization failed.

For more information on status codes, see SL STATUS DOCUMENTATION.

sl_si91x_dma_deinit#

sl_status_t sl_si91x_dma_deinit (uint32_t dma_number)

To de-initialize the DMA peripheral.

This API disables the DMA peripheral clock and interrupts. The DMA will be de-initialized only if there is no ongoing transfer.

• Pre-condition:

  • sl_si91x_dma_init must be called prior.

Returns

• sl_status_t De-initialization status:

  • SL_STATUS_OK (0x0000) - De-initialization success.

  • SL_STATUS_BUSY (0x0002) - Cannot de-initialize the peripheral due to an ongoing transfer.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

For more information on status codes, see SL STATUS DOCUMENTATION.

sl_si91x_dma_allocate_channel#

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

To allocate a DMA channel for the transfer.

This API checks the available DMA channels and allocates one. It 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 an available channel, channel_no should be initialized to 0.

• Pre-condition:

  • sl_si91x_dma_init must be called prior.

Returns

• sl_status_t Channel allocation status:

  • SL_STATUS_OK (0x0000) - Channel allocated.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

  • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

  • SL_STATUS_DMA_NO_CHANNEL_AVAILABLE (0x0046) - All DMA channels are allocated.

  • SL_STATUS_DMA_CHANNEL_ALLOCATED (0x0045) - The desired channel is already allocated.

For more information on status codes, see SL STATUS DOCUMENTATION.

sl_si91x_dma_deallocate_channel#

sl_status_t sl_si91x_dma_deallocate_channel (uint32_t dma_number, uint32_t channel_no)

To deallocate 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 must be called prior.

  • sl_si91x_dma_allocate_channel must be called prior.

Returns

• sl_status_t Channel deallocation status:

  • SL_STATUS_OK (0x0000) - Channel deallocated.

  • SL_STATUS_BUSY (0x0002) - Cannot deallocate channel due to an ongoing transfer.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

  • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.

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)

To register the DMA callbacks (transfer complete & error).

This API registers the DMA callbacks for transfer complete and error events. The 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 must be called prior.

  • sl_si91x_dma_allocate_channel must be called prior.

Returns

• sl_status_t Callback registration status:

  • SL_STATUS_OK (0x0000) - Callback registered successfully.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

  • SL_STATUS_INVALID_PARAMETER (0x000F) - Invalid channel number.

For more information on status codes, see SL STATUS DOCUMENTATION.

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)

To unregister the DMA callbacks (transfer complete & error).

This API unregisters the DMA callbacks for transfer complete and error events. Users need to update the 8-bit variable callback_type and pass it to the function. Each bit is mapped to a specific callback.

• Pre-conditions:

  • sl_si91x_dma_init must be called prior.

  • sl_si91x_dma_allocate_channel must be called prior.

  • sl_si91x_dma_register_callbacks must be called prior.

Returns

• sl_status_t Callback unregistration status:

  • SL_STATUS_OK (0x0000) - Callback unregistered successfully.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

  • SL_STATUS_INVALID_PARAMETER (0x000F) - Invalid channel number.

For more information on status codes, see SL STATUS DOCUMENTATION.

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)

To start the DMA transfer.

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

• Pre-conditions:

  • sl_si91x_dma_init must be called prior.

  • sl_si91x_dma_allocate_channel must be called prior.

  • sl_si91x_dma_register_callbacks must be called prior.

Returns

• sl_status_t DMA transfer status:

  • SL_STATUS_OK (0x0000) - Transfer started successfully.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

  • SL_STATUS_SUSPENDED (0x0004) - Transfer initialization failed.

  • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.

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)

To start a simple memory-to-memory DMA transfer.

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

• Pre-conditions:

  • sl_si91x_dma_init must be called prior.

  • sl_si91x_dma_allocate_channel must be called prior.

  • sl_si91x_dma_register_callbacks must be called prior.

Returns

• sl_status_t DMA transfer status:

  • SL_STATUS_OK (0x0000) - Transfer success.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

  • SL_STATUS_SUSPENDED (0x0004) - Transfer initialization failed.

  • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.

sl_si91x_dma_stop_transfer#

sl_status_t sl_si91x_dma_stop_transfer (uint32_t dma_number, uint32_t channel_no)

To stop the 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_STATUS_IDLE.

• Pre-conditions:

  • sl_si91x_dma_init must be called prior.

  • sl_si91x_dma_allocate_channel must be called prior.

  • sl_si91x_dma_simple_transfer or sl_si91x_dma_transfer must be called prior.

Returns

• sl_status_t DMA transfer status:

  • SL_STATUS_OK (0x0000) - Transfer stopped successfully.

  • SL_STATUS_IDLE (0x0001) - There is no active transfer on the channel.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

  • SL_STATUS_INVALID_PARAMETER (0x000F) - Invalid channel number.

For more information on status codes, see SL STATUS DOCUMENTATION.

sl_si91x_dma_channel_status_get#

sl_status_t sl_si91x_dma_channel_status_get (uint32_t dma_number, uint32_t channel_no)

To get the DMA channel status.

This API returns the status of the specified DMA channel. The possible statuses are:

• SL_STATUS_DMA_CHANNEL_ALREADY_ALLOCATED - DMA channel allocated but no active transfer in progress.

• SL_STATUS_BUSY - Channel is allocated and an active transfer is in progress.

• SL_STATUS_IDLE - Channel is not allocated.

• Pre-conditions:

  • sl_si91x_dma_init must be called prior.

Returns

• sl_status_t Channel status:

  • SL_STATUS_IDLE (0x0001) - Channel is not allocated.

  • SL_STATUS_BUSY (0x0002) - Channel is allocated and busy.

  • SL_STATUS_DMA_CHANNEL_ALREADY_ALLOCATED (0x0003) - Channel is already allocated and idle.

  • SL_STATUS_NOT_INITIALIZED (0x0004) - DMA peripheral not initialized.

  • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.

sl_si91x_dma_channel_enable#

sl_status_t sl_si91x_dma_channel_enable (uint32_t dma_number, uint32_t channel_no)

To enable the DMA channel.

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

• Pre-conditions:

  • sl_si91x_dma_init must be called prior.

  • sl_si91x_dma_allocate_channel must be called prior.

  • Transfer parameters must be configured.

Returns

• sl_status_t Channel enable status:

  • SL_STATUS_OK (0x0000) - Channel enabled successfully.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

  • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.

sl_si91x_dma_channel_disable#

sl_status_t sl_si91x_dma_channel_disable (uint32_t dma_number, uint32_t channel_no)

To disable 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 must be called prior.

Returns

• sl_status_t Channel disable status:

  • SL_STATUS_OK (0x0000) - Channel disabled successfully.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

  • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.

sl_si91x_dma_enable#

sl_status_t sl_si91x_dma_enable (uint32_t dma_number)

To enable the DMA peripheral.

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

• Pre-condition:

  • sl_si91x_dma_init must be called prior.

Returns

• sl_status_t DMA enable status:

  • SL_STATUS_OK (0x0000) - DMA enabled successfully.

  • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

For more information on status codes, see SL STATUS DOCUMENTATION.