Startup Sequence - Canon Color imageCLASS MF9170c Service Manual

3.2.2 Startup Sequence

imageCLASS MF9170c / imageCLASS MF9150c / imageCLASS MF8450c
1. Boot Program
Executed by the CPU in the main controller PCB when the main power switch is turned on.
Check the status of the image memory (DDR-SDRAM).
Load the control program from the main program ROM to the memory if the status is normal.
Display an error code when a fault is detected.
2. Control Program 1
1) Perform checking and initialization of each device (each hardware device in the main controller PCB).
2) Perform recovery of the system file as necessary when the previous shutdown was not executed normally.
In this case, it takes longer time than a normal case to start up the program.
3) Initialize each program module.
3. Control Program 2
1) Perform initialization of each software module and communication with a printer.
2) When the printer is detected normally, the startup sequence is completed.
If it is not detected normally, an error code "E197" is displayed after a connection timeout occurs.
- When E xecuting the Boot Program
Image memo ry (DDR-SD R AM)
System Image data
area
CPU
Self
diagnostic
program
program
BootROM
Main controller PCB
: a ccess to the program at time of execution.
When the startup sequence is completed, it becomes possible to receive a job. (The operation screen is displayed in the control panel, and the color of the LED of
the start key is changed from red to green.)
area
System
software
Main program
ROM
Boot
- When E xecuting the Control Program
Image memo ry (DDR-SD R AM)
System
area
CPU
Self
diagnostic
program
BootROM
: a ccess to the program at time of execution.
F-3-4
Chapter 3
Image data
area
System
software
Main program
ROM
Boot
program
0020-8295
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