Real Time Clock - Motorola 8900 - Blackberry Curve Cell Phone OEM Car Charger Developer's Manual

Real Time Clock

Real Time Clock
C24 incorporates a Real Time Clock (RTC) mechanism that performs many internal functions,
one of which is keeping time. The RTC subsystem is embedded in the PMIC and operates in all of
the C24 operating modes (Off, Idle, Sleep), as long as power is supplied above the minimum
operating level.
The C24 time and date can be set using the following methods:
Automatically retrieved from the network.
•
C24 operates in a CDMA network that supports automatic time zone updating, it will update
the RTC with the local time and date upon connection to the network. The RTC will continue
to keep the time from that point.
Using the AT+CCLK command.
•
Setting the time and date manually by this AT commands overrides the automatic network
update.
Once the time and date are manually updated, the RTC timer will keep the time and date
synchronized regardless of the C24 operating state.
When the power supply is disconnected from C24, the RTC timer will reset and the current time
and date will be lost. On the next C24 power-up the time and date will be set again automatically
or manually.
20 C24 Module Hardware Description December 15, 2008