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6.4.5 Power Up
Power up of the mobile can be initiated by one of three ways:-
1. Power Key Press
The Power key button is connected to the input KEY1 of NELL #H2. The input
(KEY1) has an internal pull-up resistor, which is grounded, when the power key
(SW20) is pressed. This then causes a failing edge on the input, which generates
an interrupt to ILB notifying it that the power key has been pressed.
2. Power up through the I/O connector - SNSINT
When an external accessory is connected to the HHP an interrupt is generated on
the SNSINT input (#7) of the system I/O connector (P5). This interrupt is then
received by ILB (#P3) of NELL (EXTSENSE).
3. Alarm Wake up
If the alarm wake up has been set by the user and it activates, then an interrupt is
generated internal to NELL and the HHP initiates its power up routine.
When an interrupt is detected by NELL from one of the aforementioned inputs
then the ILB circuit will commence its power up routine. The ILB will firstly output
a high voltage on HARD_PWR (#P2), this is then fed to the input EN2 (#28) on
MiniMoe which in-turn activates regulator 2 internally and this then powers up
the +3VNELL line. The NELL, flash PROM, and EEPROM will now power up. The
HARD_PWR signal also activates the power supply "MicrMoe" (IC204) which
supplies the outputs:2V8_RF1, 2V8_RF2 and 2V8_RF3 to sections of the RF
circuitry.
The ILB then sets the RG3VPWR (NELL- #H1) line high, which enables regulator's
3 and 7 internally within MinMoe (EN3 - #21). Both the +3VSC and +3VAUDIO
lines are now activated and so power up the CSP, DSP, SRAM (IC9) and Audio.
Once the main control devices are active the ILB enables +5VRFON (#19) and
SIMPWR (#20) to power up the 5VRF and SIMVCC lines.
6.4.6 Power Down
When the power key is pressed the interrupt is detected by KEY1 ( #H1) on NELL,
which outputs a low voltage onto the HARD_PWR, RG3VPWRN, 5VORFON and
SIMPWR control lines. This in-turn switches off the regulator's 2, 3, 5, 6, 7, and
MicroMoe (IC204), thus powering down the HHP. The power down sequence is
done in stages, so as to ensure that all data and control operations are
accomplished in order and to prevent data corruption.
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