Direct Memory Access support¶

group dma

Typedefs

typedef uint32_t dma_transfer_handle_t¶

DMA transfer handle

The DMA transfer handle is used when calling the DMA functions

Enums

enum dma_success_t¶

OpTiMSoC dma success code

The OpTiMSoC dma success code indicated the success of an operation.

Values:

enumerator DMA_SUCCESS¶

Successful operation

enumerator DMA_ERR_NOTINITIALIZED¶

Driver not initialized

enumerator DMA_ERR_NOSLOT¶

No slot available

enumerator DMA_ERR_NOTALLOCATED¶

Slot not allocated

enum dma_direction_t¶

The direction of a DMA transfer

The direction of a DMA transfer is either from local to a remote tile or vice versa

Values:

enumerator LOCAL2REMOTE¶

Transfer data from local to remote

enumerator REMOTE2LOCAL¶

Transfer data from remore to local

Functions

void dma_init(void)¶

Initialize DMA driver

Initialize the DMA driver. Necessary before calling it the first time

dma_success_t dma_alloc(dma_transfer_handle_t *id)¶

Allocate a DMA transfer slot and get handle

This function allocates a DMA slot. DMA transfers are handled asynchronously and each of the ongoing transfers is controlled by one slot in the DMA controller. You therefore need to allocate a slot before starting transfers.

Return

Success code

Parameters

• [out] id: The handle of this slot

dma_success_t dma_free(dma_transfer_handle_t id)¶

Free a pre-allocated DMA transfer slot

Return

DMA_SUCCESS if successful, any other value indicates an error

Parameters

• id: the handle to free

dma_success_t dma_transfer(void *local, uint32_t remote_tile, void *remote, size_t size, dma_direction_t dir, dma_transfer_handle_t id)¶

Initiate a DMA transfer

This function initiates a DMA transfer between the local address in this tile to remote_tile address remote of size. The direction of the transfer is determined by dir. The slot id will be used for this transfer.

Return

Success code

Parameters

• local: Local address

• remote_tile: Remote tile

• remote: Remote address

• size: Size of the transfer

• dir: Direction of the transfer

• id: Handle of the slot as allocated by dma_alloc

dma_success_t dma_wait(dma_transfer_handle_t id)¶

Blocking wait for DMA transfer

Wait for a DMA transfer to finish and block.

Return

Success code

Parameters

• id: The handle of the transfer slot