Analog Devices VisualDSP++ 5.0 Service Manual page 42

System Services Overview
• External Bus Interface Unit Control Service (EBIU) – The EBIU
control service provides a collection of routines to set up the exter-
nal interfaces of the Blackfin processor, including the SDRAM
controller. This functionality enables you to:
• Adjust SDRAM refresh and timing rates to optimal values
for given system clock frequencies.
• Set individual bus interface settings.
• Complete single function setup for known configurations,
such as the Blackfin EZ-KIT Lite platforms.
• Deferred Callback Service – The deferred callback service allows
the application to be notified of asynchronous events outside of
high-priority interrupt service routines. Using deferred callbacks
typically improves the overall I/O capacity of the system while at
the same time reducing interrupt latency. Specific functionality
allows the application to:
• Define how many callbacks can be pending at any point in
time.
• Define the interrupt priority level at which the callback ser-
vice executes.
• Create multiple callback services, each operating at a differ-
ent interrupt priority level.
• Post callbacks to a callback service with a relative priority
among all other callbacks posted to the same callback
service.
• DMA Management Service – The DMA management service
provides access into the DMA controller of a Blackfin processor.
The DMA management service allows the application to schedule
1-4 VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors