Nikon COOLPIX S550 Repair Manual page 80

1-4. SYA CIRCUIT DESCRIPTION
1. Configuration and Functions
For the overall configuration of the SYA block diagram, refer to the block diagram. The SYA block centers around a 8-bit micropro-
cessor (IC301), and controls camera system condition (mode). The 8-bit microprocessor handles the following functions.
1. Operation key input, 2. backup and clock control in case of no battery, 3. Power ON/OFF control, 4. Storobe condensor charge
control, 5. Card, USB and AV jack detection, 6. LED lighting control.
Pin Signal
1 SCK
AV JACK
2
NOT USED
3
4 NOT USED
5 HSCON
6 BEEP
LCD PWM
7
NOT USED
8
9 VDD2
10 VSS2
11
PW_LED (G)
12 BACK_LED (R)
13 MAIN RESET
14 NAND RESET
15
SCAN IN0
16
SCAN IN1
17 PW_ON
18 PLAY
19 UTX
20
NOT USED
WIDE
21
22
TELE
23 NOT USED
24 NOT USED
25 OK
26 SHUTTER 1st
27
P ON
28
PLLEN
USB_CNT
29
30 SCAN IN3
31 SCAN IN2
32 SCAN OUT2
33 SCAN OUT1
34 SCAN OUT0
35 VSS3
36 VDD3
37 (DBGP2)
38 (DBGP1/CLK)
39 (DBGP0/DATA0)
40 NOT USED
41
NOT USED
42 CARD
43
CARD ON
I/O
O Serial clock
AV JACK detection
I
- -
- -
Gyro sensor high speed charge signal
O
O Buzzer
O LCD backlight brightness current control
-
-
-
VDD2
-
VSS2
O
Power LED ON/OFF control
O Back LED (red) ON/OFF control
System reset
O
O OneNAND reset
I Keymatrix input
I Keymatrix input
POWER key detection
I
PLAY key detection
I
Debugger
O
-
-
ZOOM WIDE key detection
I
I ZOOM TELE key detection
- -
- -
I
OK key detection
Shutter 1st detection
I
D/D converter (digital system) ON/OFF signal
O
O PLL oscillation ON/OFF control
I USB insertion detection
Keymatrix input
I
I Keymatrix input
O Keymatrix output
O Keymatrix output
Keymatrix output
O
VSS3
-
- VDD3
Terminal for on-tip debugger
-
Terminal for on-tip debugger
-
-
Terminal for on-tip debugger
- -
- -
I SD card detection
Card part pull-up power
O
– 7 –
- E･ S550 -
INC
VMA21024-R.3750.A
Outline