Advantech TPC-870, User Manual

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TPC-870 User Manual 54
Table C.1: Watchdog Timer Registers
Address of
register (2E) Attribute Description
Read/Write Value (2F)
and
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 minute 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 gener-
ating an interrupt or reset signal.
Writing a new value to this register
can reset the timer to count with the
new value.
F7 (hex) rd/wr 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 automati-
cally return to 0. [default=0] Bit 4:
Read status of watchdog timer, 1
means timer is "time out".
AA (hex) ----- Write this address to I/O port 2E
(hex) to lock the watchdog timer.2