Closing Memory Streams; Visualdsp++ 5.0 Device Drivers And System; Controlling Dma Channels - Analog Devices VisualDSP++ 5.0 Service Manual

Theory of Operation
• The address of the callback function that is called when the transfer
is complete. The invocation of the callback function depends on
the callback service handle value supplied to the stream when it was
opened (either deferred or live).
If the
adi_dma_MemoryCopy()
the callback function address, the transfer occurs synchronously
and the
client until the transfer is complete. No callbacks are made in this
case.
The
ADI_DMA_2D_TRANSFER
to specify a two-dimensional transfer. This data type contains the starting
address in memory, an
a value that defines the number of rows, and
YCount
values to describe the stride for each.

Closing Memory Streams

When a memory stream is no longer needed, the
function is called to close the stream. Once closed, a stream must be
reopened before it can perform additional transfers. The client passes the
following parameters into the function:
• The stream handle. This is the value provided to the client during
the
adi_dma_MemoryOpen
• A flag to indicate whether the DMA manager should wait for the
completion of any ongoing transfers on the stream before closing
the channel

Controlling DMA Channels

Controlling DMA on a channel-by-channel basis allows for the tightest
control of DMA scheduling. Before a channel can be used, it must be
opened first and then configured.
6-10
adi_dma_MemoryCopy()
data type structure holds the necessary values
value that defines the number of columns,
XCount
function.

VisualDSP++ 5.0 Device Drivers and System

function is passed a NULL value for
function does not return to the
adi_dma_MemoryClose
Services Manual for Blackfin Processors
and
XModify YModify