AIMB-258 User Manual 58
Table A.1: Watchdog Timer Registers
Address of register (2E) Attribute
Read/Write Value (2F) and description
87 (hex) - Write this address to I/O address port 2E
(hex) twice to unlock the W83627UHG
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 num-
ber 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 sig-
nal immediately and automatically
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.