Panasonic EB-G450 Technical Manual

Also see for EB-G450: Operating instructions Service manual Operating instructions

Contents

Panasonic EB-G450 Technical Manual Manual pdf 34 page image

http://cxema.ru9.3.2 Power-up SequenceThe power-up sequence can be initiated by pressing the power key or by the presence of an external power sourceon the signal EXT_PWR. Both enable the linear regulators and the CPU becomes active. The CPU must thencheck the battery condition; if the phone is not required to power-down or sleep immediately, the result must be OKor LOW, the CPU then checks to see if a hands-free unit is connected by polling the nHF_SENSE signal, LOWwhen HF is connected.Now the CPU can make the decision whether to remain powered-up or not according to the truth-table below. Ineach case the active parameters are shaded.Batterycondition HF EXT_PWR_SENSE nIGNITION KBR0 STAY_ALIVE ModeOK X X X 1 1 activeLOW X >1.2V X 1 1 restrictedOK or LOW no >1.2V X 0 1 chargeOK yes >1.2V <0.5V 0 1 active or chargeLOW yes >1.2V <0.5V 0 1 restricted or chargeWith a hands-free, the phone can be configured via the MMI to power-up and down with transitions of the vehicleignition. These are sensed by the CPU on nIGNITION, LOW when the ignition is on.Any other state than those in the table will cause the phone to deactivate the PSU by setting STAY_ALIVE LOW.While the CPU is active, it must monitor the battery condition and accessory connectivity and change stateaccordingly.Currentmode HF EXT_PWR_SENSE nIGNITION KBR0 Batterycondition New modecharge X X X 1 OK activecharge X 1.2V X 1 LOW restrictedrestricted X X X 0 OK active9.3.3 Power-downThere are two power-down procedures;Normal power-downIn this case, the software has full control over the power-down procedure. Calls canbe terminated gracefully etc. In some cases the PSU is not deactivated but there is achange of operating modeEmergency power-downThis situation is caused by battery removal and is flagged by EXTINT. In this case theCPU only has time to perform a subset of the normal procedure. The priority is toprevent corruption of SIM dataThe truth-table for the power state transitions are shown below, the cause of a transition is shaded. In some casesthe phone does not power down completely but may enter a state of reduced functionality e.g. from active tocharge mode.When the new mode is OFF or sleep, the CPU will set STAY_ALIVE LOW.MCUK971001G8 Section 9 Issue 1Technical Guide 9 - 3 Revision 0POWER SUPPLIES