Epson EPL-5500, Service Manual

Page: 69 / 145

Table 2-1 lists the functions of the main elements of the video controller section in C169 MAIN-B
Board.
Table 2-1. Functions of C169 MAIN-B Board Main Elements
Element Location Function
MB86933H RISC
CPU IC1 The CPU, which operates at 22.5 MHz, manages the video
controller operation.
E05A91 ASIC IC2 This ASIC contains the following functions:
•
Address decoding
•
DRAM management (refresh control,
RAS/CAS control)
E05A92 ASIC IC3 This ASIC contains the following functions:
•
Video signal processing
•
Toner save function
•
BiRITech
•
EMGTech
E05A93 ASIC IC4 This ASIC contains the following functions:
•
Video interface
•
Bi-parallel interface
•
LocalTalk module control
•
Type-B EX interface box control
Two 8M ROMs or
four 4M ROMs IC21,22 or
IC13,14,15,16 These ROMs are code and font ROMs.
8M ROM IC12 This ROM is a local language (font) ROM option (except in
the U.S. model).
EEPROM IC11 This EEPROM stores the following:
•
Model type
•
Printed page counter value
•
Jam counter value
•
Printer setting
DRAM IC17,18 These DRAMs are used as the working area of the CPU:
input buffer, image buffer, etc.
Operating Principles EPL-5500 Service Manual
2-18 Rev. B