Nikon COOLPIX S550 Repair Manual page 81

44
CHG_ON
45 COMREQ/ZBOOT
46 BACKUP_CTL
47
NOT USED
48 BAT_TEMP
49
BAT_OFF
50
SREQ
51
SHUTTER 2nd
52
NOT USED
53
RESET
54
XCIN
55
XCOUT
56
VSS1
57
NOT USED
58
NOT USED
59
VDD1
60
BATTERY
61 VMONIT
62
TEMP
63
SO
64 SI
2. Setting of external port and communication
The SYA block carries out overall control of camera operation by detecting the input from the keyboard and the condition of the
camera circuits. The 8-bit microprocessor reads the signals from each sensor element as input data and outputs this data to the
camera circuits (ASIC) as operation mode setting data. Fig. 4-1 shows the internal communication between the 8-bit micropro-
cessor and ASIC.
8-bit micro processor
O Strobo charge control
I Command request
O Backup battery charge control
- -
I Battery temperature detection
Battery OFF detection signal input
I
Serial communication request signal
I
Shutter 2nd detection
I
-
-
I Backup reset detection
Clock oscillation terminal for clock (32.768 kHz)
I
Clock oscillation terminal for clock (32.768 kHz)
O
VSS1
-
-
-
-
-
VDD1
-
I Battery voltage detection
I
Main condensor charging voltage detection
Camera (SD) temperature detection
-
Serial data output
O
Serial data input
I
Table 4-1. 8-bit Microprocessor Port Specification
MAIN RESET
PLLEN
SREQ
ASIC_SDO
ASIC_SDI
SCK
COMREQ
Fig. 4-1 Internal Bus Communication System
– 8 –
- E･ S550 -
INC
VMA21024-R.3750.A
ASIC