HPCIE-C236 Half-size PICMG 1.3 CPU Card
Page 120
NOTE:
The following discussion applies to DOS environment. Contact IEI support
or visit the IEI website for specific drivers for other operating systems.
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 F-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 HPCIE-C236
Page 14: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 1 Chapter 1 1 Introduction ...
Page 23: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 10 Chapter 2 2 Packing List ...
Page 28: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 15 Chapter 3 3 Connectors ...
Page 55: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 42 Chapter 4 4 Installation ...
Page 77: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 64 Chapter 5 5 BIOS ...
Page 115: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 102 6 Software Drivers Chapter 6 ...
Page 118: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 105 Appendix A A Regulatory Compliance ...
Page 120: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 107 B Product Disposal Appendix B ...
Page 122: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 109 Appendix C C BIOS Options ...
Page 125: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 112 Appendix D D Terminology ...
Page 129: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 116 Appendix E E Digital I O Interface ...
Page 132: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 119 Appendix F F Watchdog Timer ...
Page 135: ...HPCIE C236 Half size PICMG 1 3 CPU Card Page 122 Appendix G G Hazardous Materials Disclosure ...