Function Description Of Kc-47 Board - Sony DSC-D700 Service Manual

4-8. FUNCTION DESCRIPTION OF KC-47 BOARD

Functional outline of KC-47 board
. The main function of the KC-47 board is to read a key scan signal and infrared
remote control signal by key/LCD microcomputer IC501 and control the LCD
display on the LCD panel or in the finder. Key/LCD microcomputer IC501
exchanges data by the serial communication (SH REQ (7), KY REQ (6), SH SCK
(4), SH DATA (4), and KY DATA (3)) with a main microcomputer (IC001 on the
SY-264 board).
Function description of main blocks
. Key scan block (IC501)
A key matrix is performed by signals KEY IN0 to IN5 (19 to 24) and KEY OUT0
to OUT5 (87, 88, and 91 to 94) of key/LCD microcomputer IC501. The key scan
block detects the operation of all keys and switches including the "shift dial" and
"mode dial" keys other than "power dial".
. Infrared remote control signal detection block (IC501)
The output signal from an infrared remote control photosensor (IC651 on the RM-
177 board) is passed through the IF-717 board, inverted by Q506, and input to pin
29 (SIRCS) of key/LCD microcomputer IC501. Moreover, the input signal is
noise-eliminated in IC501 and detected as a remote control signal.
. LCD control block (IC501)
In key/LCD microcomputer IC501, 48 segments (SEG0 to SEG47) and four
commons (COM0 to COM3) are provided as LCD driving output. These driving
output signals are allocated for the LCD display on the LCD panel and in the
finder so that they are controlled.
. Power management (IC501)
An SHPWR signal is output from key/LCD microcomputer IC501 to DC-DC
converter IC652 on the RM-177 board using the serial communication command
from a main microcomputer (IC001 on the SY-264 board) so as to interrupt the
power supply of the whole system. At that time, key/LCD microcomputer IC501
enables the wake-up interrupt operation to shift to the low-current consumption
mode.
. Card IN/OUT detection (IC501 and IC502)
The CD1 and CD2 signals input from a PC card are input through IC502 to pins
97 and 98 of key/LCD microcomputer IC501. The IN/OUT signal of the PC card
is detected at that time.
The supply voltage detection signals (VS1 and VS2) from a PC card are input to
pins 25 and 26 of IC501, and the detected data is directly sent to a main
microcomputer (IC001 on the SY-264 board) by serial communication.
. Supply voltage monitoring (IC501 and IC505)
Key/LCD microcomputer IC501 controls the caution display during the decrease
in a battery voltage or the power supply of the whole system during the power-on
sequence using the output signal of voltage detection circuit IC505.
4-16 DSC-D700 (UC,CE)