Nokia 6220 Service Manual

RH-20

Company confidential

System Module and User Interface

CCS Technical Documentation

Page 24

  Nokia Corporation.

Issue 1  10/2003

1AO baseband has six different functional modes:

•

 No supply

•

 

Back-up

•

 Acting Dead

•

 

Active

•

 

Sleep

•

Charging

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 > V

 or by 

connecting charger and charging the battery above V

.

In BACK_UP mode the backup battery has sufficient charge but the main battery can be 

disconnected or empty (VBAT < V

).

VRTC regulator is disabled in BACK_UP mode. VRTC output is supplied without regulation 

from backup battery (VBACK). All the other regulators are disabled in BACK_UP mode.

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.

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.

One of the sub-states of the active mode is FM radio on state. In that case, Audio Ampli-
fier and FM radio are powered on. FM radio circuitry is controlled by the MCU and 
13MHz-reference clock is generated in the UPP. VFLASH2 regulator is operating.