Canon multipass c3000 Service Manual (en)

d) Printer control section (On the PCNT board)
d-1) Printer controller (IC 5)
The main functions of the printer controller are as follows:
• Bi-centronics interface
• EEP-ROM control
• DRAM control
• Buffer control
• Print head control
d-2) MPU (IC 1)
• 16 bit CPU
• 24 bit address bus
• 16 bit data bus
• Carriage motor / Line feed motor control 
The stepping motor controller outputs the carriage motor's single- and two-phase exciter
drive signal, and paper feed motor's two-phase drive signal.
The stepping motor controller switches the carriage motor with the 5-step peak current
value for optimum driving.  The stepping motor controller outputs the switching control
signal to the carriage motor driver.
• Detection of  BJ head temperature 
• Detection of printer's internal temperature. 
• Detection of  Home position sensor, Paper edge sensor and Pickup roller sensor. 
• Cartridge detection. 
• Ink detection sensor control
d-3) ROM (IC 3)
The 8 Mbit control/CG ROM contains the program and bitmap font data for printer
d-4) DRAM (IC 4)
4 Mbit DRAM is used as the receive buffer, download buffer, print buffer, and working
d-5) EEPROM (IC 8)
Controlled by the printer controller, the 1 Kbit EEPROM (Electrically Erasable and
Programmable ROM) stores various printer emulation settings, and the waste ink amount
discharged to the waste ink absorber.
Part 1: Facsimile