Oki B 4100 Maintenance Manual page 411

IC19
Modem
IC2
IOGA
CPU
Figure A3.2.9 Interface between M17 Board and NCU Board
TXDOPE
CPU
RXDOPE
PSMODE
MPREQ
OPERST-N
IC2
OPECHK
IOGA
+5 V
0 V
PCI-N
RIINT
ACON
HUP-N
Figure A3.2.10 Interface between M17 Board and OPE (operation unit)
40055101TH Rev.4
M17
CN6
S
RP
R
CML
DP
SR
MUTE
PBXE
to OPE
OH2
to OPE
RI-N
M17 OPE
CN9 CN1
TXD
1
RXD
2
3 PSMODE
MPREQ
4
IRST
5
OPECHK
MP/OFF
6,7
8,9
13
14
15
NCU
CN3
S
A8, B8
A4, B4
A6, B6 R
A3
B3
A2
Relay driver circuit
A1
B1, B2
A15
Hook-up signal
detection circuit
A14
Ringing signal
detection circuit
X'tal
IC1
MOS CPU
Internal ROM
+5 V
GND
Eight LEDs
LEDs
Receiving
sensitivity
control
KSCAN0
to
KSCAN7
Key switch
matrix
KSENS0
to
KSENS7
DB0
to
DB7
LCD unit
Control signal
411 /