Octagon 2060 PC/104, Справочное руководство

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Watchdog function definitions using enhanced INT 17h handler
This section provides definitions for the watchdog functions using the INT17
handler (I17HNDLR.EXE). I17HNDLR.EXE is a TSR program. It is called out by
the 2060 CPU Card BIOS. Once executed it is active, but it must be executed each
time the system is rebooted. If you use a different BIOS the INT17 functions can
still be used by your application. Copy the utility to your hard drive and add it to
your AUTOEXEC.BAT.
The INT17 handler is designed for DOS based applications. If you use a different
operating system and the watchdog functions are required for your application,
source code is available in the Examples directory of the Utilities zip file to access
the watchdog. OS Development Kits are available from Octagon for Linux, QNX,
and Windows CE.net that have watchdog drivers for these operating systems.
Contact Octagon Systems for more information.
Enable watchdog
Function: fdh
Subfunction: 01h
Purpose: To enable the watchdog.
Calling registers: AH fdh
AL 01h
BX timeout (0=2 ms, 1=20 ms, 2=60 ms,
3=200 ms, 4=2 s, 5=20 s, 6=120 s, 7=na)
DX ffffh
Return registers: None
Comments: This function enables the watchdog. Once
the watchdog is enabled, it has to be strobed at
least twice per timeout period specified or until
the watchdog is disabled. Otherwise, a system
reset will occur.
Programming example:
/* Inline assembly code for Borland C++ 3.1 */
/* set watchdog to two second timeout */
asm {
mov ax,0fd01h
mov bx,4
mov dx,0ffffh
int 17h
}
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