Circular Buffer Callback Options; Buffer Data Types - Analog Devices VisualDSP++ 5.0 Service Manual

Circular Buffer Callback Options

The next section in the
of callback the client requests when the device manager is using the circu-
lar buffer dataflow method.
Enumerations are provided indicating the device manager should make no
callbacks, make a callback on sub-buffer completions, or make a callback
on whole buffer completions.

Buffer Data Types

The
ADI_DEV_1D_BUFFER
data structures are used to provide data buffers to the driver. At the
BUFFER
top of these data structures is a reserved area that allows the device drivers
access to a small amount of memory attached to each buffer. How (or if)
the device driver uses this reserved area depends on the implementation.
Note that if the physical device driver is supported by peripheral DMA,
the device manager uses this reserved area to create a DMA descriptor
describing the buffer. This descriptor is, in turn, passed to the DMA man-
ager system service in order to use DMA to move the data, as described in
the buffer structure.
If the physical driver is not supported by peripheral DMA, the physical
driver can use this reserved area for any purpose—for example, queue
management or whatever mechanism the physical driver uses to move the
data.
Also included in this section is a
represents a union of one-dimensional, two-dimensional, and circular
buffers. This data type is used as a convenient method to refer to a buffer
in a generic fashion, without knowing the specific type of buffer. The
and
dev_Read adi_dev_Write
type when passing buffers to these functions.
VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors
file contains enumerations for the type
adi_dev.h
,
ADI_DEV_2D_BUFFER
ADI_DEV_BUFFER
API functions use the
Device Driver Manager
, and
ADI_DEV_CIRCULAR_
data structure, which
ADI_DEV_BUFFER
adi_
data
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