Data Types; Adi_Dma_Channel_Handle; Adi_Dma_Descriptor_Union And Adi_Dma; Descriptor_Handle - Analog Devices VisualDSP++ 5.0 Service Manual

Public Data Structures, Enumerations, and Macros

Data Types

Several data types that shield the client developer from the internal imple-
mentation of the library and the details of DMA programming are used.
These data types also provide an interface that is partially decoupled from
the functionality offered by individual processors.

ADI_DMA_CHANNEL_HANDLE

The
ADI_DMA_CHANNEL_HANDLE
channel to the DMA manager. When passed to the DMA manager func-
tion, it uniquely identifies the channel function to which it needs to refer
or upon which it must operate. The DMA manager returns this handle to
the application when a DMA channel is opened. All other DMA manager
functions that need to identify a channel require this parameter to be
passed.
ADI_DMA_DESCRIPTOR_UNION and
ADI_DMA_DESCRIPTOR_HANDLE
The
ADI_DMA_DESCRIPTOR_UNION
small descriptor, large descriptor, and descriptor array data types. The
ADI_DMA_DESCRIPTOR_HANDLE
the union. The
adi_dma_Queue()
a) a small descriptor chain, b) a large descriptor chain, or c) an array of
descriptors. By using the handle/union, a single
tion is needed, instead of separate functions for each of the descriptor data
types.
typedef union ADI_DMA_DESCRIPTOR_UNION {
ADI_DMA_DESCRIPTOR_SMALL
ADI_DMA_DESCRIPTOR_LARGE
6-54
data type identifies each separate DMA
data structure represents a union of the
is then a
ADI_DMA_DESCRIPTOR_HANDLE
function as a means to provide the function with
VisualDSP++ 5.0 Device Drivers and System
that describes a pointer to
typedef
is passed into the
adi_dma_Queue()
Small;
Large;
Services Manual for Blackfin Processors
func-