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x1:
Circuit sequence
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Power ON
1. When the power is supplied, if the input voltage is 3V or
more, the power voltage is supplied to the IC21
(RSSRMSH458) 6 PIN (VOD) to output the regulate voltage
of SV.
This VOUT voltage is supplied to each element as +5VOC.
(Power system diagram)
2. When +5VOC is supplied, the power is supplied to the ASIC,
starting oscillation of X2. The ASIC then tums DC ON signal
active (from LOW to HIGH). When, however, the VCCD
FAULT signal or the BAT FAULT signal is inputted to the
ASIC, the DC ON signal tums non-active (from HIGH to
LOW). If LOW signal is not inputted to the VCC FAULT and
the BAT FAULT, the DC ON remains HIGH and is inputted to
the IC16 (UMC4), turning the IC15 input (2 pin) HIGH, sup-
plying 3.3V from the IC15 3 pin to the 40MHz oscillator (X1),
starting oscillation of X1.
3. When the address buses of the CPU (ARM610), the ASIC,
the SRAM, and the ROM operate normally, and when all
data buses operate normally, and when the ROM data are
rad normally, the ASIC outputs the LCD OC CLK from 36 pin.
This LCD DC CLK signal serves as the reference oscillation
clock for each booster circuit.
After that, the ASIC tums 31 pin LCDLVCON to HIGH, ac-
tivating the LVC (SC3611), and displaying the LCD screen.
The system is started in the above sequence.
2: When the power is tumed off by the software:
1, When the power is turned off by the power switch operation
'on the OS, or when it is tumed off during a diag operation,
the ASIC pertorms OFF process of each gate, tums the DC
ON to LOW, and stops 40MHz clock. After that, the RAM, the
ASIC, etc. are backed up by +5VOC.
2. This state is held until the command of power ON is given to
the ASIC by POWER SW operation or software control. How-
ever, when the power voltage falls below 3V, the IC23 inputs
the LOW level of BAT FAULT signal to the ASIC. In this
case, the system is not restarted until the input voltage rises
to 3V or more. in addition, the memory data are not retained
if the backup voltage is supplied. The current which is sup-
plied from the input power to the unit is the OFF current of
the unit.
«3;
When the backup battery is set, the power is turned off by the
software, and the input power voitage is cut off:
The circuit operates similarly to the descriptions in x2. When the
input power voltage is cut off, the backup battery supplies the
power to +5VOC.
The current which is supplied from the backup battery to the unit
is the backup current of the unit.
Note: This circuit operations are based on the third trial model.
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