– 11 –
ASIC,
memory
CCD
8bit
CPU
LCD
MONITOR
Power supply voltage
Power OFF
Playback mode
Shooting
USB connection
1.20 V, 3.25 V
12 V, -6 V
3.3 V
3.2 V
3.25 V
OFF
OFF
32 KHz
OFF
ON
OFF
4 MHz
ON
ON
OFF
4 MHz
ON
ON
ON
4 MHz
ON
ON
OFF
4 MHz
OFF
Table 5-3. Power supply control
Shooting mode (LCD)
4. Power Supply Control
The 8-bit microprocessor controls the power supply for the overall system.
The following is a description of how the power supply is turned on and off. When the battery is attached, IC501 is operating and
creating 3.6 V, a regulated 3.2 V voltage is normally input to the 8-bit microprocessor (IC301) by IC302, clock counting and key
scanning is carried out even when the power switch is turned off, so that the camera can start up again.
When the power switch is off, the 8-bit microprocessor halts 4 MHz of the main clock, and operates 32.768 kHz of subclock.
When the battery is removed, the 8-bit microprocessor power switches the lithum secondary battery for memory backup by
IC302, and operates at low consumption. At this condition, the 8-bit microprocessor halts 4 MHz of the main clock, and operates
32.768 kHz clock counting by subclock.
Also, the battery for backup is charged 10 hours from it to be attached.
When the power switch is on, the 8-bit microprocessor starts processing. The 8-bit microprocessor first sets both the PON signal
at pin (30) and the PAON signal (ASIC) to High, and then turn on the power circuit. After PON signal is to High, sets external port
of ASIC after approximately 100 ms. According to setting of this external port, carry out setting of the operating frequency and
oscillation control in the ASIC. Also, it starts communication with ASIC, and confirms the system is operative.
When the through image is operating, set the PAON signal (ASIC) to High and then turn on the CCD. When the through image is
playing, set the PAON signal to Low and then turn off the CCD. When LCD panel turns on, set BL ON signal at pin (41) to High,
and turn on the backlight power.
When the power switch is off, the lens will be stowed, and PON, PAON and BLON signals to Low and the power supply to the
whole system is halted. The 8-bit microprocessor halts oscillation of the main clock (4 MHz), and set operation mode of clock
ocillation (32.768 kHz).
Table 5-2. Key Operation
3. Key Operaiton
For details of the key operation, refer to the instruction manual.
1
2
0
1
2
3
SCAN
OUT
SCAN
IN
UP
-
TELE
PW_TEST
LEFT
WIDE
-
RIGHT
SCENE
MENU
0
-
DOWN
4
OK
PLAY
PW_ON
