Programming The Watchdog Timer; Watchdog Timer; Configuration Register - Aaeon SBC-658 User Manual

Programming the watchdog timer

Watchdog timer

The watchdog timer uses a 8-bit counter. The time range is from 32
seconds to 254.5 min with a resolution of 1 min. When timer times
out, a system reset will happen.

Configuration register

The watchdog timer of SBC-658 is located on the chipset – Win-
bond W83977TF. If you want to use it, you have to know how to
read/write the configuration register of W83977TF. The basic
procedure is as follows.
1. Enter configuration mode.
2. Select Logical Device.
3. Select register number.
4. Write/read data to/from register.
5. Exit configuration mode.
To Enter/Exit the configuration mode is to write a specific value to
configuration port — 3F1h.
Enter configuration mode: write value 87h to configuration port
twice.
Exit configuration mode: write value aah to configuration port.
96 SBC-658 User Manual