Advantech PCE-5130, Руководство пользователя

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69 PCE-5130 User Manual
Appendix A
P
rogramming
the
W
atchdog
Timer
Table A.1: Watchdog timer registers
Address of
register (2E) Attribute
Read/Write
Value (2F)& description
87 (hex) -----
Write this address to I/O address port 2E (hex) twice to
unlock the W83627HF
07 (hex) write Write 08 (hex) to select register of watchdog timer.
30 (hex) write
Write 01 (hex) to enable the function of the watchdog
timer. Disabled is set as default.
F5 (hex) write
Set seconds or minutes as units for the timer. Write 0 to
bit 3: set second as counting unit. [default]. Write 1 to bit
3: set minutes as counting unit
F6 (hex) write
0: stop timer [default]
01~FF (hex): The amount of the count, in seconds or
minutes, depends on the value set in register F5 (hex).
This number decides how long the watchdog timer waits
for strobe before generating an interrupt or reset signal.
Writing a new value to this register can reset the timer to
count with the new value.
F7 (hex) read/write
Bit 6: Write 1 to enable keyboard to reset the timer, 0 to
disable.[default]
Bit 5: Write 1 to generate a timeout signal immediately
and automatically return to 0. [default=0]
Bit 4: Read status of watchdog timer, 1 means timer is
“timeout”.
AA (hex) -----
Write this address to I/O port 2E (hex) to lock the watch-
dog timer 2.