The master reset threshold controls the internal reset of Retu / (Tahvo). If battery voltage is above VMSTR,Tahvo’s charging control logic is alive. Also, RTC is active and supplied from the main battery. Above VMSTR,Tahvo allows the system to be powered on although this may not succeed due to voltage drops during startup. SW can also consider battery voltage too low for operation and power down the system.Power keyThe system boots up when power key is pressed (adequate battery voltage, VBAT, present).Power down can be initiated by pressing the power key again (the system is powered down with the aid ofSW). Power on key is connected to Retu ASIC via PWRONX signal.RM-42System Module Nokia Customer Care9241872 (Issue 1) Company Confidential Page 9–13Copyright ©2005 Nokia. All Rights Reserved.