Closing A Dma Channel; Transfer Completions - Analog Devices VisualDSP++ 5.0 Service Manual

• The command ID. This
controllable item that is configured.
• A command-specific value. The semantics of this parameter are
defined by the command ID. For example, given a command ID of
ADI_DMA_CMD_SET_DATAFLOW
or
TRUE
command-specific value is always cast to (

Closing a DMA Channel

To close a DMA channel, the client calls the
The client passes the following parameters into the function:
• The channel handle. This is the value provided to the client during
the
adi_dma_Open()
• A flag indicating whether the DMA manager should wait for any
DMA activity on the channel to complete before closing the
channel.
Once a channel has been closed, the channel must be reopened with the
adi_dma_Open()

Transfer Completions

Client applications can use two different mechanisms to determine when
transfers complete. One method is by polling the channel, and the other
method is through callbacks.
In addition to polling and callbacks, the memory stream functions offer a
synchronous capability. When used synchronously, the
adi_dma_MemoryCopy()
the client only when the transfer is complete.
VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors
ADI_DMA_CMD
, to enable or disable dataflow on the channel. The
FALSE
function.
function before it can be used again.
and
adi_dma_MemoryCopy2D()
data type identifies the
, the command-specific value is either
void*
adi_dma_Close()
DMA Manager
).
function.
functions return to
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