Introduction - Analog Devices VisualDSP++ 5.0 Service Manual

Introduction

Introduction
The DMA manager provides the application developer with the means
to manage DMA traffic on as many channels as required across the
spectrum—from setting up the DMA channels for their intended purpose,
to providing callbacks to the client application on transfer completion.
As part of the system services, the DMA manager provides a complete and
easy-to-use interface to the DMA controller. To this end, the DMA man-
ager is designed to:
• Remove the need for direct client access to memory-mapped regis-
ters (MMRs) through the implementation of application
programming interface (API) function calls.
• Place no limitations on the type of data transfer. All descriptor
types are supported as well as single and circular buffers. Both
one-dimensional (1-D) and two-dimensional (2-D) DMA can be
used.
• Provide a simple interface to perform block copies of data between
different memory locations using both 1-D and 2-D memory
DMA, such that blocks of data can be copied between internal and
external memory with one function call in an equivalent manner to
the C library
• Interpret interrupts raised on DMA transfer completion and pass
higher-level event information to user-supplied callback functions.
For example, if an interrupt is raised on each inner loop of a
circular 2-D DMA transfer, an event can be passed to the callback
function at the completion of each inner loop.
6-2
function.
memcpy
VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors