FALCON™ X3
4
4.10 SUSPEND
MANAGEMENT
Suspend Management allows the user to keep device features powered while
the device is off. The term "device off" here refers to a condition where the
display is off and the device appears unpowered. The device CPU may in fact
be powered on. The features managed by this feature are: Cellular Data/Voice
and GPS.
NOTE
The WiFi driver has been measured to consume about 50 µA
when left powered. As a result, WiFi will always be left powered
during suspend. This has the positive effect of substantially
reducing the time required for WiFi to fully resume when the
device is powered back on.
Normally, the device features will behave the same as today. This means when
the device is powered off, certain features (such as cellular communications)
will remain powered if enabled prior to the device powering off. The behavior of
each feature left powered during suspend is as follows:
•
Power is not removed from the feature.
•
It can act as a wakeup source for the CPU. When the CPU wakes up, the
device continues to appear "off", but the device driver on the CPU can
interact with the feature.
•
Depending on what activity takes place, any feature can optionally decide
to change the system power state from Suspend to On. This would appear
to the user as a wakeup event.
When the user powers off the device by pressing the power key, the behavior
begins similar to today:
•
The user is required to press the power key for at least 500 ms.
•
After this much time, the red suspend LED turns on to provide user
feedback that the power key has been recognized.
If the user releases the power key in the next 1.5 seconds, the system
completes the shutdown of the CPU and device features will remain powered. If
instead the user continues to hold down the power key for a total of at least two
seconds, then the following pop-up dialog will be displayed:
The user is given five seconds to respond. If the user selects "Yes", then the
device and all features are powered off. If the user selects "No", or does not
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