Power Key And System Power Up; Modes Of Operation - Nokia RM-596 Service Manual

Voltage
Higher extreme voltage
(fast charging)
Vmstr+
Vmstr-
Sw shutdown
Sw shutdown
Vcoff+
Vcoff-

Power key and system power up

When the battery is placed in the phone, the power key circuits are energized. When the power key is pressed,
the system boots up (if an adequate battery voltage is present).
Power down can be initiated by pressing the power key again and the system is powered down with the aid
of SW. The power key is connected to EM ASIC (N2200) via the PWRONX signal.
The PWRONX line cannot be detected when SW hangs. For that reason, the user has to remove the battery.
Because the semi-fixed battery is difficult to remove, a fixed delay circuit Resetto IC (N2400) is used. The
PWRONX is also connected to Resetto. When the user presses the power key beyond 7.5 secs, it generates a
reset which is connected to EM ASIC's UserResetX line. The UserResetX is entirely HW controlled, so even when
SW hangs, the phone can be powered down by pressing the power key beyond 7.5 sec.

Modes of operation

Mode
NO_SUPPLY (Dead) mode means that the main battery is not present or its voltage is too low (below
N2200 master reset threshold) and that the back-up battery voltage is too low.
BACK_UP The main battery is not present or its voltage is too low but back-up battery is adequate
and the 32 kHz oscillator is running.
PWR_OFF In this mode (warm), the main battery is present and its voltage is over N2200 master
reset threshold. All regulators are disabled, PURX is on low state, the RTC is on and the
oscillator is on. PWR_OFF (cold) mode is almost the same as PWR_OFF (warm), but the
RTC and the oscillator are off.
RESET RESET mode is a synonym for start-up sequence. RESET mode uses 32 kHz clock to count
the RESET mode delay (typically 16ms).
SLEEP SLEEP mode is entered only from PWR_ON mode with the aid of SW when the system's
activity is low.
FLASHING FLASHING mode is for SW downloading.
Page 6 – 12
Voltage [V]
4.230
HW Shutdown Voltages
2.1 ± 0.1
1.9 ± 0.1
SW Shutdown Voltages
3.15
3.25
Min Operating Voltage
2.9 ± 0.1
2.6 ± 0.1
COMPANY CONFIDENTIAL
Copyright © 2010 Nokia. All rights reserved.
Condition
Off to on
On to off
In call
In idle
Off to on
On to off
Description
RM-596
System Module
Issue 2