Panasonic KX-FT21BX

KX-FT21LA
- 146 -
IC1
ASIC
DIGITAL BOARD OPERATION BOARD
READ POSITION SENSOR
DOCUMENT SENSOR
CN6 CN1
CN7 CN2
(Chip on board type)
ANALOG SW
IC1
CN3
8X4
KEYS
MATRIX
LCD
9. OPERATION PANEL
The unit consists of an LCD (Liquid crystal display), KEYs, photo interrupters (sensor), and analog switches (for key scan).
The key scan (analog switch control, reading), sensor detection (sensor control, reading) and LCD control are all controlled by
I/O of ASIC (IC1) on the digital board.
Fig .a.
10-1. KEY SCAN
When CN1(8) (OPSEL) is "H", the analog switch (IC1) is available. The "KLATCH", "KSCLK" and "KTXD" control the analog
switch (IC1) to read at KIN0~3.
Analog Switch (IC1) Control
Key Matrix
0
KIN0
KIN1
KIN2
KIN3
MONITOR
4
7
(SW7)
(SW14)
(SW22)
(SW29)
1
8
2
5
(SW6)
(SW13)
(SW21)
(SW28)
FUNCTION 3
VOLUME
LOW
LOWER
VOLUME
HIGH
(SW5)
(SW12)
(SW20)
(SW27)
STOP
MODE
START/
COPY/SET
(SW8)
(SW15)
(SW30)
DIRECTORY
FUNCTION 1
FUNCTION 2
(SW11)
(SW19)
(SW26)
RESOLUTION
HELP
RECEIVE
MODE
(SW1)
(SW16)
(SW23)
0
9
6
3
(SW3)
(SW10)
(SW18)
(SW25)
FLASH
REDIAL/
PAUSE
#
(SW2)
(SW17)
(SW24)
1234567
01234567
KLATCH(A)LHLHLHLH
KSCLK(B) L L H H L L H H
KTXD(C) L L L L H H H H