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There are four main power states that the HHP can be set into. These are :-
1. ILB Reset
When the battery is disconnected (or very low), the ILB is held in a reset state via
the generation of an ILB reset pulse from MinMoe (UVLO2OUT-#22). Only the real
time clock remains in operation. The rest of the HHP, including the NELL and
3VSC supply, is powered off. Hence the ILB will not respond to any asynchronous
event such as key-presses etc. In this mode the ILB may be powered from the
back-up battery if the main battery voltage is too low e.g. (<UVLO1 threshold,
2.6V-2.85V).
2. Hard off
In this mode a charged battery has been fitted or re-charged to a level greater
than the UVLO2 threshold ( 2.85V-3.1V) or the charger connected. The ILB is
operational, but the remainder of the HHP, including the NELL, flash ROM,
EEPROM and the main 3VSC supply is powered down.
3. Soft off
In Soft off mode the CPU in NELL has removed power from large portions of the
HHP's circuitry and the 13mhz clock is also disabled. This is achieved by the
suspension of the HARD_PWR (NELL#P2) signal which inturn di-activates both
regulator 2 internal to MiniMoe and IC204 (MicroMoe). The ILB has a "sleep "
function that allows its operation to be suspended for short periods of time.
If while the ILB is in "sleep" mode an asynchronous event is detected such as:
keypad press etc, then it will automatically re-activate and continue operation.
4. On
In this mode all the logic circuit is powered and the RF sections are switched on
as required.
The different modes and power states are illustrated in table.2
Functional Block
13 Mhz clock and driver
RF
CSP
DSP
NELL (ILB)
NELL (CPU)
EEPROM
CPU FLASH ROM
CPU SRAM
SIM
LCD DISPLAY
LED's
Back-Light
Back-up Battery
Table 2 - DB2000 Power States
ILB Reset
Hard Off
OFF
OFF
OFF
OFF
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
Powering ILB
Kept charged from the
battery via Reg 1.
Soft Off
OFF
OFF
OFF
OFF
OFF
In Idle state
OFF
In S/W stop mode.
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
OFF
ON
OFF
ON
OFF
OFF
OFF
OFF
Kept charged from
the battery via Reg 1.
On
ON
RF sections powered
on as needed.
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
Kept charged from
the battery via Reg 1.
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