H8DCE User's Manual Watch Dog Enable/Disable JWD controls the Watch Dog function. Watch Dog is a system monitor that can reboot the system when a software application hangs. Pins 1-2 will cause WD to reset the system if an applica- tion has frozen. Pins 2-3 will generate a non-maskable interrupt signal for the application that is frozen. See the table on the right for jumper settings. Watch Dog must also be enabled in BIOS (set- ting located in the Power Menu). Note: When enabled, the user needs to write their own application software in or- der to disable the Watch Dog timer.
Onboard Speaker Enable/Disable The JF2 header allows you to use either an external speaker or the internal (onboard) speaker. To use the internal (onboard) speaker, close pins 5 and 7 with a jumper. To use an external speaker, connect the speaker wires to pins 1 through 7 of JF2. See the table on the right for settings and the table associated with the Power LED/Keylock/Speaker connection (previous section) for pin defi nitions. 2-18 Watch Dog Jumper Settings (JWD) Jumper Setting Defi nition Pins 1-2 Reset Pins 2-3 NMI Open Disabled Onboard Speaker Enable/Disable Pin Defi nitions (JF2) Pins Defi nition 5 and 7 Jump for onboard speaker 1,3,5,7 Attach external speaker wires