After inserting the main battery, regulators started by HW are enabled. SW checks, if there is some reason to
keep the power on. If not, the system is set to power off state by watchdog. Power up can be caused by
• Power key is pressed
• Charger is connected
• RTC alarm occurs
• MBUS wakeup
CellMo engine (WG4.1M) is master during power up sequence i.e. CellMo side makes the decision when phone
is powered on. RSTX signal from AVilma is used to enable the startup sequence of Rel3.1 engine. The rising
edge of RSTX starts all the resources needed to boot RAPIDOYawe and Nomadik chips.
The actual power-up sequence is shown below.
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