Modes Of Operation - Nokia RM-57 Service Manual

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Signal
Back-Up supply voltage

Modes of operation

Mode Description
NO_SUPPLY (dead) mode means that the main battery is not present or its voltage is too low (below
RETU 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 voltage is
adequate and the 32kHz oscillator is running (RTC is on).
PWR_OFF In this mode (warm), the main battery is present and its voltage is over RETU 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. In this mode certain regulators are
enabled and after they and RFClk have stabilized, the system reset (PurX) is released and
PWR_ON mode entered. RESET mode uses 32kHz clock to count the REST 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. There are in principle three different sleep modes:
• Helen3 sleep
• RAP3G sleep
• OMAP and RAP3G sleep (deep sleep)
In SLEEP mode RETU's regulators VIO, VDRAM, VSIM1, VSIM2, VAUX and Vana are in low
quiescent current mode (output voltages still present but regulators will not give as much
current out). Other regulators including VR1 supplying system clock oscillator are
disabled.
In SLEEP mode, TAHVO VCORE SMPS regulator is in low quiescent current mode (if sleep
mode is not internally disabled). Linear regulator VOUT state depends on the accessory
connected to the system connector (Pop-Port), if there is any.
FLASHING FLASHING mode is for SW downloading. FLASHING mode is not really a RETU or TAHVO
state but rather a system state. From RETU and TAHVO point of view, it is like PWR_ON.
The state is entered from PWR_ON. It is possible to use external voltage (VPP) during
flashing to speed up the process (provided that the memory components support the
feature).
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Copyright ©2005 Nokia. All Rights Reserved.
Unit Notes
2.7 V Maximum capacity of the backup
power supply assumed to be 200
µAh.
RM-57/58
System Module
Issue 1