User Guide

CCS Technical Documentation System Module
RH-25
Issue 1 10/2003 ©Nokia Corporation Confidential Page 5
Figure 1: RH-25 baseband block diagram
Functional Description
Modes of Operation
The RH-25 baseband engine has five different operating modes:
1 No supply
2Acting Dead
3Active
4 Sleep
5 Charging
No Supply Mode
In NO_SUPPLY mode, the phone has no supply voltage. This mode is due to the discon-
nection of main battery or low battery voltage level. The phone will exit from
NO_SUPPLY mode when a sufficient battery voltage level is detected. The battery voltage
UEM
IHF
UPP
Combo Memory
64Mbit
Flash/4Mbit SRAM
T
ACO RF Module
Audio Amp
Battery
Keyboard
(UI Module)
IrDa
1.8V
LCD
Passive color STN
color display
System connector
Tomahawk
DC
jack
Charger
Accessory
Regulator
2.8V 70mA
IHF
Led Driver
Keyboard &
display
illumination
V
ibra
Ext Audio
Connector