Sony CBK-HD01 Maintenance Manual page 19

10. Info battery communication circuit.
This equipment supports batteries with SM Bus
specifications. The serial communication bus (SDA, SCL)
for IC916 (Parallel bus to I2C_bus Controller) connected
to the FP_CPU bus passes through IC927 and IC928
(switching switch) and connects to the serial terminal of
the info battery. The Serial Clock Rate is 88 KHz.
The battery type, remaining time, and other information is
loaded onto FP_CPU and transmitted to ITRON (CPU).
ITRON (CPU) calculates the remaining battery charge and
creates remaining charge display data, and transmits the
data to Camera CPU and FP_CPU. FP_CPU displays the
remaining charge display data on the monochrome LCD.
The remaining charge display data can be checked at the
same time in the status menu for the color LCD.
11. Power off software control circuit
FP_CPU detects the POWER-SW OFF information. When
power can be turned on, the "Power OFF" command is sent
from ITRON (CPU) and FP_CPU controls the power OFF
circuit on the CNB-25 board.
12. FP_CPU backup circuit
Even when power is turned off for FP_CPU, the data is
saved for the internal RAM and Real Time Clock (RX-
8025NB) through backup on a coin battery. By saving the
system data, FP_CPU can be started up quickly when the
power is turned on.
BATTERY
INFO_ BATT
F
_SDA
E
INFO_BATT
Battery
_SCL
ID Register
+
+3 V
FET-SW
(CNB-25 board)
Battery-in
DC-in
+5 V
Front
Microphone
Volume
SW-1425
PDW-700/V1 (E)
IC927
IC916
IC928
SW
PCA9564
I2C_BUS
A
SDA
CPU_BUS
B
D7
:
D0
A
SCL
B
IC914
Voltage
measurement
+3 V
IC838
Battery Voltage
ID Data
measurement
IC839
Voltage
UNREG+12 V
measurement
IC7
Voltage
measurement
to iTRON_CPU
Voltage Measurement Block Overview
13. Backup lithium battery voltage measurement circuit
FP_CPU performs voltage measurement on the backup
lithium battery. When recharging is detected, the reduced-
voltage information is send to ITRON (CPU).
(Measurement interval time: 60 s)
Current is prevented from running through FET-SW
(Q836) in order to prevent power from being lost during
measurement. Furthermore, reverse current above +3 V is
prevented with FET-SW (Q829), thus extending the life of
the lithium battery. The battery life is guaranteed for about
5 years.
14. FP_CPU independent operations
When the POWER-SW is set to power off, power is
supplied from the UNSW +12 V power circuit to display
the counter and other information on the monochrome
LCD. Power is supplied to each power regulator with
IC830 (hyposaturation regulator 8 V) and independent
operations can be performed. The operations can be turned
on or off from the menu.
15. REAR input control
The serial communication bus (SDA, SCL) for IC917
(Parallel bus to I2C_bus Controller) connected to the
FP_CPU bus sends control for the AXM-38 board through
the motherboard with IC202 (PCA-9555: I2C_I/O_PORT)
on the CNB-25 board and acquires the following
information: REAR_XLR automatic insertion detection
Vcc
IC844
Port
FET-SW
8 bit
AN15
D15
:
Port
D8
(1 time/60 sec)
IC921
HD64F2378
CPU
Port
CLOCK 16 MHz
AN11
Voltage measurement
AN8
AN14
Voltage measurement
AN9
AN13
AN0
AN1
AN2
FRONT,REA,WRR-SW1,2,3,4
AN3
AN4
FREE,SET,REC_RUN-SW
AN5
PRESET,REGENE,CLOCK-SW
AN10
AN6
AN7
+3 V
+3 V
(IC805)
Q829
Q836
FET-SW
Lithium
Coin
IC908
Battery
Real Time
+3 V
Clock
RX-8025NB
+3 V
CH-1
RV1
+3 V
CH-2
RV2
CTL,TC,U_BIT-SW
Monitor-SW
(3 digitize level)
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