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)

Initialize DMA peripheral by enabling DMA clock and clearing DMA interrupts.

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)

Deinitialize the DMA module by disabling peripheral clock and interrupts, if there is no ongoing DMA transfer.

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)

Check the available DMA channel and allocate the channel.

This function also sets the priority of allocated channel and assign the channel number to *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. To allocate the available channel, channel_no should be initialized to 0.

• This function should be called after initializing DMA using 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 - 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)

Deallocate the DMA channel if there is no ongoing transfer on 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)

Register DMA callbacks (transfer complete & error).

Users must update the sl_dma_callback_t structure and pass its address to this function. Users can have separate callbacks for transfer complete and error for each channel.

• This function should be called after sl_si91x_dma_init and 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)

Unregister DMA callbacks (transfer complete & error).

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

Returns

• channel deallocation 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)

Configure the DMA channel descriptor and initiate DMA transfer.

DMA primary descriptor is updated in this function and based on transfer mode the alternate descriptor is also updated (only for ping pong mode). Additionally, other DMA parameters such as peripheral ACK signal (for peripheral memory transfers), DMA priority etc. are also updated.

• This function should be called after sl_si91x_dma_init and sl_si91x_dma_allocate_channel

Returns

• DMA transfer status SL_STATUS_OK - Transfer started successfully SL_STATUS_SUSPENDED - Transfer initialization fail 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)

Configure the DMA channel descriptor and initiate simple memory to memory DMA transfer.

Pass the source address and destination address of transfer along with transfer length in bytes.

• This function should be called after sl_si91x_dma_init and sl_si91x_dma_allocate_channel

Returns

• DMA transfer status SL_STATUS_OK - Transfer success SL_STATUS_SUSPENDED - Transfer initialization fail 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)

Stop any active transfer on a channel.

If there is no active transfer on the channel, this function returns SL_DMA_CHANNEL_IDLE.

• This function should be called after sl_si91x_dma_init and sl_si91x_dma_allocate_channel

Returns

• DMA transfer status SL_STATUS_OK - Transfer stopped successfully SL_STATUS_IDLE - There is no active transfer on 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)

Return the channel status i.e., whether the channel is allocated/busy/idle.

• This function should be called after 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