Operation; Initialization; Termination - Analog Devices VisualDSP++ 5.0 Service Manual

Parameter checking in the debug versions of the system services library
provides a more complete test of API function parameters and for condi-
tions that may cause errors. Analog Devices strongly recommends that
development work be done using the debug versions of the system service
library, while final test and deployment be done with the release version of
the library.

Operation

This section describes the overall operation of the timer service. Details on
the application programming interface (API) can be found later in this
chapter.

Initialization

Prior to using the timer service, the client must first initialize the service.
In order to initialize the service, the client passes to the initialization func-
tion,
adi_tmr_Init()
should the timer service need to protect a critical region of code, and
optionally a contiguous piece of memory that the service can use for flag
callbacks.
The timer service provides a facility where, if so directed by the client, a
callback function supplied by the client can be invoked should a timer
expire. See the
callbacks operate. Unlike some other services in which the client provides
memory to the service for use by the service, the timer service requires no
additional memory.

Termination

When the client no longer requires the functionality of the timer service,
the termination function,
uninstalls any installed timer callbacks and closes any open timers.
VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors
, a parameter is passed to the critical region function
"Callbacks" on page 8-7
adi_tmr_Terminate()
Timer Service
for more information on how
, is called. This function
8-3