Controller Operating Principles - Epson ColorPage EPL-C8000 Service Manual

EPSON EPL-C8000

2.8 Controller Operating Principles

This section describes the C235MAIN board, the MAIN CONTROLLER
PWB of the EPL-C8000.
The main functions of the C235MAIN board are as follows:
n Processing print commands and print data sent from the host
computer.
n Producing image video signals
n Controlling and driving each mechanism in the engine to print
image on paper, synchronizing with the signals from the engine
controller side (MCU PWB).
The printer is equipped with the data bus 64-bit RISC CPU "R4700-
133MHz" for the processor and a168-pin SDRAM module
(CLK:66MHz), which is becoming a major module used for desk top
personal computer, for memory. Combining those equippements, the
printer has secceeded in processing data on the C235MAIN board at a
higher speed.
Specific to color print, one page of data processed is more than 4 times
as large as in monochrome print. Since the data to process is so heavy,
the printer has a high-speed image procossor ASIC on the C235MAIN
board for a faster color image data processing. With this ASIC
equipped, the conputer side is less loaded in processing data, and the
CPU on the C235MAIN board also processes color image data with a
less load. (The 2UP mode equipped with the printer allows the engine to
run 2 pages (A4/LETTER) at a time.)
See Figure 2-54 for the C235MAIN board circuit diagram and Table
2-25 and Table 2-26 for the major components on the C235MAIN board
and their functions.
Chapter 2 OPERATING PRINCIPLES
Rev. B
2-76