Canon W6400 Series Service Manual Download Page 71

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Chapter 2

2-27

2.4.3 Engine Controller

2.4.3.1 Engine controller components

0008-6354

F-2-30

a) CPU (IC511)

The CPU, with a 32-bit internal bus, operates in synchronization with the 132-MHz internal clock that is generated from a 66-MHz external clock.

The CPU is used 8-MB SDRAM (IC508), 8-MB FLASH MEMORY (IC503) and 32-KB EEPROM (IC704). The CPU performs parameter control and

has the following functions.

Timer function

This function is used for the cleaning functions.

The internal RTC (IC725) and lithium battery (BAT501) allow the timer to operate even when the AC power supply is off for performing the cleaning

function.

EEPROM control function

In addition to the EEPROM (IC704) with on-board, it controls the six color independent ink tank EEPROM, maintenance cartridge EEPROM, and head

EEPROM.

Ink tank level detection

This function detects the remaining ink level for each color based on the signals from the electrodes mounted on the hollow needle.

I/O port

This function performs I/O control from the sensors.

b) ASIC (IC512)

The ASIC, with a 32-bit internal bus, operates in synchronization with the 100-MHz internal clock that is generated from a 50-MHz external clock.

It uses two 32MB SDRAMs and two 8MB SDRAMs having the following functions:

System controller communication control

This function controls communication with the system controller.

Image data reception

This function receives the image data from the system controller and stores it in the SDRAM (IC501, IC502).

Image data generation/output

This function generates the image data for printing each color from the image data received from the system controller and mask pattern corresponding to

the print mode in the SDRAM (IC501, IC502) and stores it in SDRAM (IC506, IC507).

This function also controls the output of the generated image data to the carriage relay PCB.

Heat enable signal control

This functions uses the pulse width to perform variable control of the time that the heat enable signal is applied to the nozzle heater board for each nozzle

array in the printhead.

Linear scale count

This function reads the linear scale when driving the carriage, divides the 150lpi timing signal by eight to generate the 1200lpi timing signal. It also counts

the linear scale timing cycle using the reference clock to measure the carriage driving speed.

Dot count

This function counts the discharge dots used as information for the heat enable signal function, maintenance jet control, cleaning function, and remaining

ink level for each nozzle array.

PWM control

This function performs driving control of the carriage motor, and suction fan and temperature control of the printhead based on the control signals from

the CPU.

Feed motor control

This function controls 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) Driver ASIC (IC705, IC706)

The image data generated by the ASIC (IC512) undergoes differential processing to reduce noise and then is sent to the carriage relay PCB.

d) SDRAM (IC508)

IC506

IC707

IC507

IC503