Watchdog Timer
57
5
Watchdog Timer
The NuPRO-796 implements a watchdog timer embedded in the
LPC based SMSC SCH3112 Super I/O controller.
The Watchdog timer contains of a one-second/minute resolution
down counter. The Watchdog output is connected to "RESET".
When the system hangs up without software re-trigger, the system
will be reset. So basically this is a watchdog timer that has a 1 sec-
ond granularity up to 255 seconds or a 1 minute granularity up to
255 minutes. Optionally any movement of keyboard, mouse can
reload the timer value and restart the countdown process. Count-
down can be stopped by writing the value 0 to the value register.
To configure the registers, the following sequence should be fol-
lowed :
1. Writing 0Eh to IO port 847h to setup WDT mode (stan-
dard mode on booting is WDT-off or GPIO mode 01h
value in 847h)
2. Writing 06h to IO port 867h to enable reset of countdown
by mosue/keyboard interrupt
3. Writing 80h (minutes) or 00h (seconds) to IO port 865h
to configure the granularity
4. START Counter : write value 1~255 to IO port 866h to
set timer value and start countdown
5. RESET Counter : write any 1~255 to IO port 866h to
reset timer value and start countdown
6. STOP Counter : write any 0 (zero) to IO port 866h to
stop countdown and disable WDT
Summary of Contents for NuPRO-796 Series
Page 4: ......
Page 13: ...Introduction 5 1 4 NuPRO 796 Functional Diagram Figure 1 1 NuPRO 796 Block Diagram ...
Page 14: ...6 Introduction 1 5 NuPRO 796 Mechanical Diagram Figure 1 2 NuPRO 796 Carrier Board Layout ...
Page 28: ...20 Connectors and Jumpers ...
Page 45: ...Phoenix Award BIOS 37 4 5 3 Onboard Audio Enable or Disable ...
Page 68: ...60 Watchdog Timer ...
