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2-8
PPPPSM System Overview
Programmer’s Manual
selected. It will continue execution from the point when it was put into stopped
state.
2.8.3
Task Swapping
Task swapping is performed by PPSM transparent to the application programmer.
A task swapping is executed when an application, other than the actively running
application, needs to become active. This normally occurs when PPSM kernel
receives an interrupt, such as timer or user pen-down.
For example, when an application icon for a new application is pressed, the task
that is actively running will be put into stopped state and the new task will become
active.
2.9
Timer Management
PPSM maintains a reprogrammable clock that is defaulted to 9:00am 1
st
of
January, 1997 upon start up. This clock is incremented in 1 second interval aFigure 3-1
never stops.
A set of timer tools are available for time management. This allows the
programmer to set system clock, clock alarm, time-out, and input time-out in their
application.
Personal Portable System Manager
Programmer’s Manual
3-1
PPSM Programming
PPSM programming mainly consists of two parts:
PPSM initialization and applications integration
Individual PPSM application programming
A PPSM system must first be initialized before any PPSM tools and resources can
be assigned and used. System integrators may choose to integrate multiple
individual PPSM applications into one PPSM system. For example, a simple
PPSM organizer may consist of applications such as address book, calendar,
scheduler and calculator.
shows a typical PPSM system start up flow. First, PPSM must be
initialized, then applications to be integrated onto the system must be registered
with PPSM individually. The last step to get the system going is to start the
application which is chosen to run first.
3.1.1
PPSM Initialization
The PPSMInit() tool performs all the internal resources initialization and interrupt
Figure 3-1 PPSM System Start Up Flow Chart
F
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
.