Aaeon ETX-821 Manual page 36

E T X C P U M o d u l e
Hardware Reset Hardware Reset Hardware Reset
Wait for key string Wait for key string Wait for key string
N N N
Is the data "87h"? Is the data "87h"? Is the data "87h"?
N N N
N N N
There are three steps to complete the configuration setup: (1)
Enter the MB PnP Mode; (2) Modify the data of configuration
registers; (3) Exit the MB PnP Mode. Undesired result may
occur if the MB PnP Mode is not exited normally.
(1) Enter the MB PnP Mode
To enter the MB PnP Mode, four special I/O write operations
are to be performed during Wait for Key state. To ensure the
initial state of the key-check logic, it is necessary to perform
four write opera-tions to the Special Address port (2EH). Two
different enter keys are provided to select configuration ports
I/O write to 2Eh I/O write to 2Eh I/O write to 2Eh
Y Y Y
Check Pass key Check Pass key Check Pass key
I/O write to 2Eh I/O write to 2Eh I/O write to 2Eh
Next Data? Next Data? Next Data?
Y Y Y
Last Data? Last Data? Last Data?
Y Y Y
MB PnP Mode MB PnP Mode MB PnP Mode
Appendix A Programming the Watchdog Timer
E T X - 8 2 1
Any other I/O transition cycle Any other I/O transition cycle Any other I/O transition cycle
Any other I/O transition cycle Any other I/O transition cycle Any other I/O transition cycle
A - 3