Motorola 8900 - Blackberry Curve Cell Phone OEM Car Charger, Developer'S Manual

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Low Power Mode
18 C24 Module Hardware Description December 15, 2008
Temporary Termination of Low Power Mode
Temporary termination of low power mode occurs when C24 switches from Sleep mode to Idle
mode for a defined period, and then returns automatically to Sleep mode.
Low power mode may be terminated temporarily by several sources, some of which are user
initiated and others are initiated by the system.
Using the WKUPI_N signal
The WKUPI_N signal is an active low input, which is set high by default. By asserting this signal
low the application can wake-up C24 from low power mode and switch to Idle mode.
C24 will remain in Idle mode, awake and fully active, as long as WKUPI_N signal remains low.
When this signal is disabled and set high again, C24 will return to Sleep mode automatically,
according to the ATS24 settings (see
Figure 2-8 ).
Figure 2-8: WKUPI_N Signal Operation
The WKUPI_N signal is the recommended method to temporarily wake-up C24 from low power
mode. It provides the application full control of the C24 operating mode and guarantees that data
on the serial interface will not be lost or misinterpreted.
The WKUPI_N signal must be used to wake up C24 from low power mode if the serial interface
has been disabled by the AT+MSCTS command.
Incoming Network Data
During low power mode, C24 continues monitoring the CDMA network for any incoming data,
message or voice calls.
When C24 receives an indication from the network that an incoming voice call, message or data
is available, it automatically wakes up from low power mode to alert the application. When C24
has completed to process all the tasks related to the incoming data, it will automatically return to
low power mode according to the ATS24 settings.
Depending on the type of network indication and the application settings, C24 may operate in
several methods, which are configurable by AT commands, to alert the application of the
incoming data:
•
Enable the WKUPO_N signal to wake-up the application from low power.