Ope (04W) Circuit Diagram - Oki OKIFAX4550 Maintenance Manual

5.

OPE (04W) Circuit Diagram

1. Block diagram
Figure A.31 shows a block diagram of OPE (04W).
The 04W (operation unit) circuit consists of the following blocks:
1) IC1 (one chip MOS-CPU)
• Output ports
Setting LEDs on and off: 8 ports
Specifies the row during key switch matrix scanning: 8 ports
• Input ports
Detect the column whose key is pressed: 8 ports
2) Key switch matrix (8 rows x 8 columns)
3) LEDs (8 LEDs)
4) LCD unit
2. Key switch scanning
Output ports (KSCAN0 to KSCAN7 signal) corresponding to 8 rows of key matrix are scanned
sequentially by the software. In the case 1 is any of output from KSCAN0 to KSCAN7 signal
which corresponds to the row 8 in the block diagram, the software reads input port, KSENS0 to
KSENS7, and determines which in the row 8 is pressed.
3. LED drives and LEDs
Eight LEDs (ALARM, PHOTO, LIGHT, etc.) on the control panel are driven by output of IC1 via
resistors R1, R4-9 and R11 respectively. An LED lights on when a port output is 1.
4. In case sub-power supply is applied to the fax machine: when PC1-N, HUP-N or RIINT signal
is input to OPE unit, OPE unit controls the main power supply (TLHV board) by outputting the
MP/OFF (ACON) signal.
• PC1-N:
• HUP-N:
• RIINT:
41309401TH Rev.4
Presence of document on hopper
OFF-Hook detection for TEL 1 and TEL 2 terminal
Ringing detection signal
OPE (04W)
CN1
IC1
1 TXDOPE
2 RXDOPE
5 OPECHK
13 PC1-N
MOS CPU
Internal ROM
4 OPERST
3 PSMODE
15 HUP-N
14 RIINT
12 MP/OFF
Eight LEDs
Figure A.31 Block Diagram of OPE (Operation Unit)
KSCAN0
to
X'tal
KSCAN7
Key switch
matrix
KSENS0
to
KSENS7
DB0
to
DB7
LCD unit
Control signals
LEDs
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