User Guide

Issue 1 12/04 COMPANY CONFIDENTIAL 23

RAE-6/RA-4

6 - Baseband Description and Troubleshooting Nokia Customer Care

Operating modes

• NO_SUPPLY mode means that the main battery is not present or its voltage is

too low (below UEMEK master reset threshold limit) and back-up battery voltage is

too low.

• In BACK_UP mode the main battery is disconnected or empty but back-up battery

has sufficient charge in it

• IN POWER_OFF mode the main battery is present and its voltage is over UEMEK

master threshold limit. All regulators are disabled. Device can enter in Power Off –

mode e.g. due to thermal shutdown or watchdog elapsing or VBAT falling below

VCOFF-.

• RESET mode is a synonym for start-up sequence and contains in fact several

modes. In this mode certain regulators and system oscillators are enabled and after

they have stabilized, the system reset (PURX) is released and PWR ON mode en-

tered.

• In POWER_ON mode SW is running and controlling the system

• SLEEP mode is entered only from PWR ON mode when system activity is low.

CMT and APE sides can be in sleep mode independently from each other.

Power up sequence

RESET mode can be entered in three ways: by inserting the battery or charger, or by RTC

alarm.