User Guide

PAMS
Technical Documentation
NSB–1
System Module
Page 3 – 19
Original 06/98
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.
Before battery voltage voltage rises over 3.0 V Charging Logic
gives an initial charge (with limited current) to the battery. After
battery voltage reaches that voltage limit the power up proce-
dure is as described in the previous chapters.
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.
When the CCONT is activated, it switches on the baseband supply volt-
age and generates a power up reset signal PURX to the MAD. When the
PURX reset is released, the MAD releases the system reset ExtSysReset
and the internal MCUResetX signals and starts the boot program execu-
tion. If booting is succeeded program execution continues from flash pro-
gram memory. When the phone is powered up with an empty battery pack
using the standard charger, the charger may not supply enough current
for standard power–up procedure and the power–up must be delayed.
Acting Dead
If the phone is off when the charger is connected, the phone is powered
on but enters a state called ”acting dead”. To the user the phone acts as if
it was switched off. A battery charging alert is given and/or a battery
charging indication on the display is shown to acknowledge the user that
the battery is being charged.
Active Mode
In the active mode the phone is in normal operation, scanning for chan-
nels, listening to a base station, transmitting and processing information.
All the CCONT regulators are operating. There are several substates in
the active mode depending on if the phone is in burst reception, burst
transmission, if DSP is working etc..