Start-Up Sequence - Canon imageRUNNER 2270 Service Manual

Chapter 4

4.3.2 Start-Up Sequence

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<Boot ROM Area>
- Self Diagnosis Program (interval 1)
The self-diagnosis program is run by the CPU on the main controller PCB when the main
power switch is turned on.
The program is used to check the condition of the image memory (SDRAM) and the
HDD.
The machine will indicate an error code if it finds a fault while running the program.
- Boot Program (interval 2)
When the self-diagnosis program ends normally, the CPU on the main controller PCB
executes the boot program.
The program is used to read the system software from the HDD to write it into the image
memory (SDRAM).
<Image Memory (SDRAM) Area> (interval 3)
The system software written by the boot program initializes the various functional blocks
(e.g., I/F settings of the main controller).
When all the foregoing ends normally, the machine becomes ready to accept a job
(i.e., the control panel shows the Operation screen, and the LED on the Start key changes
from red to green).
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