Oki OKIFAX 5400 Maintenance Manual page 305

OPE
CPU
from NCU
to Main power supply
(AC ON)
40838301TH Rev.1
E17
CN9
TXD
1
2
RXD
5
OPECHK
13
PC1-N
from PC1
4
OPERST
PSMODE 3
HUP-N 15
RIINT
14
MP/OFF 12
Figure A3.2.1 Block Diagram of OPE (operation unit)
OPE (05W)
X'tal
CN1
IC1
1
2
5
13
MOS CPU
Internal ROM
4
3
15
14
12
Eight LEDs
LEDs
A3 - 24
KSCAN0
to
KSCAN7
Key switch
matrix
KSENS0
to
KSENS7
DB0
to
DB7
LCD unit
Control signals