Canon W8400 Series, Service Manual, Page: 82 / 224

Chapter 2
2-32
This function performs rotation detection of the encoder slit after passing through the motor driver and control of the feed motor speed and position based
on the control signals from the CPU.
I/O port
This function performs I/O control from the sensors and controls the driving units of the motors, clutch, solenoids, and other parts.
c) SDRAM (IC15, IC16)
The 8MB SDRAM is connected to the 32-bit data bus and is used as a receive buffer and mask data buffer when receiving the print data.
d) SDRAM (IC11, IC12, IC13, IC14)
The 32MB SDRAM is connected to the 32-bit data bus and is used as an image buffer that converts data when receiving the print data.
e) FLASH MEMORY (IC3)
The 8-MB FRASH MEMORY is connected to the 16-bit data bus and stores a printer control program and mask patterns.
f) SDRAM(IC2)
The 8-MB SDRAM is connected to the 32-bit data bus and is used as a CPU work memory.
g) EEPROM(IC28)
The 32-Kbit EEPROM stores the printer adjustment values.
h) Regulator IC(IC25)
The regulator IC generates the CPU and ASIC internal driving power supply (3.3 V)
i) Regulator (IC31)
The regulator IC generates the CPU and ASIC internal driving power supply (1.8 V)
j) RTC (IC7)
Used as timer.
k) Reset IC (IC7)
Initializes the power on engine controller.
l) Lithium battery (BAT1)
The lithium battery is connected to the RTC in the CPU. The battery can performs backups for approximately three months with the AC power
unconnected.
m) Driver IC (IC17, IC18, IC19, IC20, IC21)
Sends image data received by ASIC (IC4) to carriage relay board.
2.4.4 Carriage Relay PCB
2.4.4.1 Carriage relay PCB components
0009-1528
F-2-33
a) Receiver IC (IC203, IC204, IC205, IC206)
Receives image data sent from engine controller driver IC (IC17, IC18).
b) Regulator IC (IC211)
The regulator IC is used to generate the discharge drive power supply (18 V) of the printhead from +26.5 V.
IC5
IC204
IC205
IC206
IC203
IC351
IC211
Q211
IC2 IC6 IC8 IC9 IC3
IC7
IC4