Introduction - Analog Devices VisualDSP++ 5.0 Service Manual

Introduction

Introduction
Using the capabilities of other system services, the timer service allows the
client to control and coordinate the all timers in a consistent fashion,
regardless of processor derivative. The service also provides the means for
clients to install callback functions that are notified upon timer
expirations.
Use of the timer service is dependent on the use of both the interrupt
manager and the deferred callback (DCB) manager for its full operation.
If callbacks are not deferred, but rather are live, the DCB manager is not
required. If callbacks are not required, neither the interrupt manager nor
DCB manager is required.
In order to reduce the pin count of devices, timer pins are sometimes
muxed onto the same pins as other peripherals. The timer service does not
provide arbitration functionality to control pin muxing. It is the responsi-
bility of the client program to ensure that peripherals and the timer service
do not use the same pin simultaneously. For ADSP-BF531/532/533 and
ADSP-BF561 processors, this entails ensuring that the relevant peripheral
control registers are correctly set. For ADSP-BF534/536/537 processors,
the timer service automatically invokes the port control service to affect
any pin mux changes. No user intervention is required.
The timer service uses an unambiguous naming convention to safeguard
against conflicts with other software libraries provided by Analog Devices
or elsewhere. All enumeration values and
prefix, and functions and global variables use the lowercase
ADI_TMR_
equivalent.
adi_tmr_
Each function within the timer service application program interface
(API) returns an error code of the type
services, a return value of 0 (
A nonzero value indicates an error. Like all system services, timer service
error codes are unique from all other system services. The
include file lists all error codes that the timer service returns.
8-2
typedef
ADI_TMR_RESULT
ADI_TMR_RESULT_SUCCESS
VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors
statements use the
. Like all system
) indicates no errors.
adi_tmr.h