Altera Embedded Peripherals IP - Manual (Page 208)

Table 21-14: Descriptor Data Structure
typedef struct {
alt_u32 *read_addr;
alt_u32 read_addr_pad;
alt_u32 *write_addr;
alt_u32 write_addr_pad;
alt_u32 *next;
alt_u32 next_pad;
alt_u16 bytes_to_transfer;
alt_u8 read_burst; /* Reserved field. Set to 0. */
alt_u8 write_burst;/* Reserved field. Set to 0. */
alt_u16 actual_bytes_transferred;
alt_u8 status;
alt_u8 control;
} alt_avalon_sgdma_packed alt_sgdma_descriptor;
SG-DMA API
Table 21-15: Function List
Name Description
alt_avalon_sgdma_do_async_transfer()
Starts a non-blocking transfer of a descriptor chain.
alt_avalon_sgdma_do_sync_transfer()
Starts a blocking transfer of a descriptor chain. This
function blocks both before transfer if the controller
is busy and until the requested transfer has
completed.
alt_avalon_sgdma_construct_mem_to_
mem_desc
()
Constructs a single SG-DMA descriptor in the
specified memory for an Avalon-MM to Avalon-
MM transfer.
alt_avalon_sgdma_construct_stream_
to_mem_desc
()
Constructs a single SG-DMA descriptor in the
specified memory for an Avalon-ST to Avalon-MM
transfer. The function automatically terminates the
descriptor chain with a NULL descriptor.
alt_avalon_sgdma_construct_mem_to_
stream_desc
()
Constructs a single SG-DMA descriptor in the
specified memory for an Avalon-MM to Avalon-ST
transfer.
alt_avalon_sgdma_check_descriptor_
status()
Reads the status of a given descriptor.
UG-01085
2014.24.07
SG-DMA API 21-17
Scatter-Gather DMA Controller Core Altera Corporation
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