HELP - Watchdog Timer Function

  • Thread starter Thread starter Desi
  • Start date Start date
D

Desi

Everyone,

I have an EBX single board computer that has an on-board watchdog
function. In order to keep the watchdog alive and prevent a system
reboot, the vendor claims that you must "tickle" Interrupt 15
periodically.

They provide code to do this in various environments, but not in
Windows XP or any Win32 environment.

I'm not sure where to start... What approach would you use to do this?
Do I need to write a driver to be able to access the interrupt?

~Desi

Here is what the manufacturer's documentation had to say:

· During System Operation - An application can set up the WDT
hardware through a BIOS call, or by accessing the hardware directly.
Some Board Support Packages provide an API interface to the WDT. The
application must tickle (turnoff) the WDT in the time set when the WDT
is initialized or the system will be reset. You can use a BIOS call to
tickle the WDT or access the hardware directly.

The BIOS implements interrupt 15 function 0C3h to manipulate the WDT.
 
What is the time period in which the WDT must be "tickled" before it decays
to the point of performing a HW reset?

Del

Everyone,

I have an EBX single board computer that has an on-board watchdog
function. In order to keep the watchdog alive and prevent a system
reboot, the vendor claims that you must "tickle" Interrupt 15
periodically.

They provide code to do this in various environments, but not in
Windows XP or any Win32 environment.

I'm not sure where to start... What approach would you use to do this?
Do I need to write a driver to be able to access the interrupt?

~Desi

Here is what the manufacturer's documentation had to say:

· During System Operation - An application can set up the WDT
hardware through a BIOS call, or by accessing the hardware directly.
Some Board Support Packages provide an API interface to the WDT. The
application must tickle (turnoff) the WDT in the time set when the WDT
is initialized or the system will be reset. You can use a BIOS call to
tickle the WDT or access the hardware directly.

The BIOS implements interrupt 15 function 0C3h to manipulate the WDT.
 
I can set it from 1 - 255 seconds. This should be more than enough to
get through boot-up and load whatever software does the "Tickling".

I'm just not sure how to implement the software...
 
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