Composition Of The System Software - Canon iR8500 Service Manual

CHAPTER 3 MAIN CONTROLLER
When the self-diagnosis ends, the boot program that is also stored on the hard disk is
started to read the system software from the hard disk to the system area of the SDRAM.
When done, the system software of the SDRAM is started to initialize the parts; thereaf-
ter, the control panel shows the normal Operation screen and, at the same time, the Start key
LED changes from red to green to indicate that the machine is ready to accept a job.
The machine's system software consists of multiple modules, and those modules that are
needed at a time are called into the system area of the SDRAM for execution.

1.3.3 Composition of the System Software

The machine's system software can broadly be divided into system modules (for control)
and language modules (for LCD indication).
Upgrading of the system software calls for upgrading both system and language modules;
for details, see 6. "Upgrading" in Chapter 6 "Troubleshooting."
3-6
SD RAM
System Image data
area area
CPU
Self-
Boot
diagnosis
program
program
BOOT ROM
Main controller PCB
: Access to the program during execution
: Flow of the system program
F03-103-03
COPYRIGHT© 2001 CANON INC.
HDD
2000 2000 2000 2000 CANON iR8500/7200 REV.1 AUG. 2001