PPC-37xx-N270 Panel PC
Page 136
NOTE:
The following discussion applies to DOS environment. IEI support is
contacted or the IEI website visited for specific drivers for more
sophisticated operating systems, e.g., Windows and Linux.
The Watchdog Timer is provided to ensure that standalone systems can always recover
from catastrophic conditions that cause the CPU to crash. This condition may have
occurred by external EMIs or a software bug. When the CPU stops working correctly,
Watchdog Timer either performs a hardware reset (cold boot) or a Non-Maskable Interrupt
(NMI) to bring the system back to a known state.
A BIOS function call (INT 15H) is used to control the Watchdog Timer.
INT 15H:
AH – 6FH Sub-function:
AL – 2:
Sets the Watchdog Timer’s period.
BL:
Time-out value (Its unit-second is dependent on the item “Watchdog
Timer unit select” in CMOS setup).
Table C-1: AH-6FH Sub-function
Call sub-function 2 to set the time-out period of Watchdog Timer first. If the time-out value
is not zero, the Watchdog Timer starts counting down. When the timer value reaches zero,
the system resets. To ensure that this reset condition does not occur, calling sub-function
2 must periodically refresh the Watchdog Timer. However, the watchdog timer is disabled
if the time-out value is set to zero.
A tolerance of at least 10% must be maintained to avoid unknown routines within the
operating system (DOS), such as disk I/O that can be very time-consuming.
Summary of Contents for PPC-3708A-N270
Page 14: ......
Page 15: ...PPC 37xx N270 Panel PC Page 1 Chapter 1 1 Introduction ...
Page 24: ...PPC 37xx N270 Panel PC Page 10 Chapter 2 2 Detailed Specifications ...
Page 38: ...PPC 37xx N270 Panel PC Page 24 3 Unpacking Chapter 3 ...
Page 42: ...PPC 37xx N270 Panel PC Page 28 4 Installation Chapter 4 ...
Page 77: ...PPC 37xx N270 Panel PC Page 63 5 BIOS Screens Chapter 5 ...
Page 123: ...PPC 37xx N270 Panel PC Page 109 Chapter 6 6 Driver Installation ...
Page 140: ...PPC 37xx N270 Panel PC Page 126 A Safety Precautions Appendix A ...
Page 145: ...PPC 37xx N270 Panel PC Page 131 Appendix B B BIOS Options ...
Page 149: ...PPC 37xx N270 Panel PC Page 135 Appendix C C Watchdog Timer ...
Page 152: ...PPC 37xx N270 Panel PC Page 138 Appendix D D Hazardous Materials Disclosure ...