Baseband Functional Description; Modes Of Operation; No Supply; Backup - Nokia NSB-9 Service Manual

NSB-9
System Module and User Interface

Baseband Functional Description

Modes of Operation

NSB-9 baseband has six different functional modes:

• No supply

• Back-up

• Acting Dead

• Active

• Sleep
• Charging
No supply
In NO_SUPPLY mode the phone has no supply voltage. This mode is due to disconnection
of main battery and backup battery or low battery voltage level in both of the batteries.
Phone is exiting from NO_SUPPLY mode when sufficient battery voltage level is detected.
Battery voltage can rise either by connecting a new battery with VBAT > VMSTR+ or by
connecting charger and charging the battery above VMSTR+.

Backup

In BACKUP mode the backup battery has sufficient charge but the main battery can be
disconnected or empty (VBAT < VMSTR and VBACK > VBUCOFF).
VRTC regulator is disabled in BACKUP mode. VRTC output is supplied without regulation
from backup battery (VBACK). All the other regulators are disabled.
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
In the active mode the phone is in normal operation, scanning for channels, listening to
a base station, transmitting and processing information. There are several sub-states in
the active mode depending on if the phone is in burst reception, burst transmission, if
DSP is working etc.
Page 24
Nokia Corporation
CCS Technical Documentation
Issue 1 04/03