Canon iR5570 Series, Service Manual

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Chapter 4
4-5
4.3 Start-Up Sequence
4.3.1 Overview
0009-3793
The system software used to control the machine is stored on the HDD.
When the machine is started, the CPU on the main controller PCB reads the system software from the HDD according to the instructions of the boot ROM
boot program, and writes it to the image memory (SDRAM) of the controller PCB.
While the CPU reads the system software from the HDD to the image memory (DRAM), the control panel shows the following screen, using a progress
bar to indicate the progress of the start-up sequence.
F-4-5
Do not turn off the main power while the progress bar is indicated, as access is being made to the HDD. Turning off the power can cause a fault on the
HDD (identified by E602).
4.3.2 Start-Up Sequence
0009-3794
<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).
Progress bar