R46 Circuit Diagram (Okioffice87); R46 Circuit Diagram (1/15, 2/15, 3/15) - Oki OKIFAX4550 Maintenance Manual

4.

R46 Circuit Diagram (OKIOFFICE87)

4.1

R46 Circuit Diagram (1/15, 2/15, 3/15)

1. Block diagram
R46-PCB circuit diagram (1/15, 2/15, 3/15) shown the consists of an input/output gate array IC2
(IOGA6), crystal oscillator circuit and reset signal generator.
Figure A.19 shown the block diagram of IC2 (IOGA6) and the peripheral circuits.
2. Function
1) IOGA6 is newly developed LSI for scanning, printing control and provided with a built-in
CPU.
- IOGA6 contains the following functions:
• Scanned data DMA control
• Strobe signals control for LED head
• Smoothing control for printing data
• Interface of the peripheral LSI
- CPU
CPU controls the following functions in addition to the basic processor.
• DMA (Direct Memory Access) control
• Interrupt procedure control
• A/D converter
• Bus state control
• Programmable pattern control
• 16 bit integrated timer pulse unit (ITU)
• Timing pattern control (TPC)
• Serial communication interface (SCT)
2) Crystal oscillator circuit
X1 is 20MHz crystal oscillator. The output wave is fed to the CPU1 through pin 73 and 74.
CLK (20MHz) signal output from pin 71 is used as the system clock.
+5V
Data/Address Bus
Various Sensor
Data/Address Bus
Data/Address Bus
41309401TH Rev.4
Address Bus
Initial Reset Circuit
IC1
POWRDY
X1
XTAL
EXTAL
20 MHz
Buffer 640 bytes
(RLE,TIFF,ACC32)
200-300 converter
Peripheral control
Figure A.19 Related Signals of IOGA6
CPU; SH7034
CLK CLK
20 MHz
IOGA6 1/3
Printer control
OST-EX
M D-motor
Decoding
smoothing
IOGA6 2/3
1284 control
CS generation
I/O port
DMA 2ch
IOGA6 3/3
High-voltage
Controller
Data/Address bus
LED head
300 dpi
Clutch
Bi-Centro
I/F
OPE unit
Speaker
High-voltage
Power Supply
331 /