PPC-37xxA-N26 Panel PC
Page 179
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 EMI 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 D-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. While 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-37 A-N26 Series
Page 17: ...PPC 37xxA N26 Panel PC Page 1 1 Introduction Chapter 1 ...
Page 29: ...PPC 37xxA N26 Panel PC Page 13 2 Unpacking Chapter 2 ...
Page 34: ...PPC 37xxA N26 Panel PC Page 18 3 Installation Chapter 3 ...
Page 72: ...PPC 37xxA N26 Panel PC Page 56 Chapter 4 4 System Maintenance ...
Page 76: ...PPC 37xxA N26 Panel PC Page 60 5 BIOS Setup Chapter 5 ...
Page 106: ...PPC 37xxA N26 Panel PC Page 90 6 Driver Installation Chapter 6 ...
Page 133: ...PPC 37xxA N26 Panel PC Page 117 7 Interface Connectors Chapter 7 ...
Page 145: ...PPC 37xxA N26 Panel PC Page 129 A BIOS Configuration Options Appendix A ...
Page 148: ...PPC 37xxA N26 Panel PC Page 132 Appendix B B One Key Recovery ...
Page 156: ...PPC 37xxA N26 Panel PC Page 140 Figure B 5 Partition Creation Commands ...
Page 189: ...PPC 37xxA N26 Panel PC Page 173 C Safety Precautions Appendix C ...
Page 194: ...PPC 37xxA N26 Panel PC Page 178 D Watchdog Timer Appendix D ...
Page 197: ...PPC 37xxA N26 Panel PC Page 181 E Hazardous Materials Disclosure Appendix E ...