Deferred Callback Manager; Introduction - Analog Devices VisualDSP++ 5.0 Service Manual

5 DEFERRED CALLBACK
MANAGER
This chapter describes the deferred callback (DCB) manager used by the
application developer to manage the deferred execution of function calls.
A detailed description of the application programming interface (API)
provided by the deferred callback manager is included.
This chapter contains:
• "Introduction" on page 5-1
• "Using the Deferred Callback Manager" on page 5-3
• "Interoperability With an RTOS" on page 5-8
• "DCB Manager API Reference" on page 5-12
• "Public Data Types and Macros" on page 5-25

Introduction

Callback functions are commonly used in event-driven applications where
the client application requests that a service manager (such as the system
services library's (SSL) DMA manager) notifies it upon completion of a
requested task, for example the completion of DMA transfer, by means of
a client callback function specified by the client application upon initializa-
tion of the required service.
The need to execute a client callback function normally occurs while exe-
cuting an interrupt service routine (ISR) at relatively high priority. The
general rule for such ISRs is to keep the amount of time spent in them as
VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors
5-1