Nokia Mobile Phones NSE-5 Series, Service Manual, Page: 35 / 327

PAMS
Technical Documentation
NSE–5
System Module
Page 2 – 21
Issue 1 07/99
Power Up
The baseband is powered up by:
1. Pressing the power key, that generates a PWRONX interrupt
signal from the power key to the CCONT, which starts the pow-
er up procedure.
2. Connecting a charger to the phone. The CCONT recognizes
the charger from the VCHAR voltage and starts the power up
procedure.
3. A RTC interrupt. If the real time clock is set to alarm and the
phone is switched off, the RTC generates an interrupt signal,
when the alarm is gone off. The RTC interrupt signal is con-
nected to the PWRONX line to give a power on signal to the
CCONT just like the power key.
4. A battery interrupt. Intelligent battery packs have a possibility
to power up the phone. When the battery gives a short (10ms)
voltage pulse through the BTEMP pin, the CCONT wakes up
and starts the power on procedure.
Power up with a charger
When the charger is connected CCONT will switch on the CCONT digital
voltage as soon as the battery voltage exeeds 3.0V. The reset for
CCONT’s digital parts is released when the operating voltage is stabilized
( 50 us from switching on the voltages). Operating voltage for VCXO is
also switched on. The counter in CCONT digital section will keep MAD in
reset for 62 ms (PURX) to make sure that the clock provided by VCXO is
stable. After this delay MAD reset is relased, and VCXO –control
(SLEEPX) is given to MAD. The diagram assumes empty battery, but the
situation would be the same with full battery:
When the phone is powered up with an empty battery pack using the
standard charger, the charger may not supply enough current for standard
powerup procedure and the powerup must be delayed.
Power Up With The Power Switch (PWRONX)
When the power on switch is pressed the PWRONX signal will go low.
CCONT will switch on the CCONT digital section and VCXO as was the
case with the charger driven power up. If PWRONX is low when the 64 ms
delay expires, PURX is released and SLEEPX control goes to MAD. If
PWRONX is not low when 64 ms expires, PURX will not be released, and
CCONT will go to power off ( digital section will send power off signal to
analog parts)