ICE-BDE-T7 COM Express Module
Page 84
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 E-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 ICE-BDE-T7
Page 11: ...ICE BDE T7 COM Express Module Page 1 Chapter 1 1 Introduction...
Page 19: ...ICE BDE T7 COM Express Module Page 9 Chapter 2 2 Packing List...
Page 23: ...ICE BDE T7 COM Express Module Page 13 Chapter 3 3 Connectors...
Page 40: ...ICE BDE T7 COM Express Module Page 30 Chapter 4 4 Installation...
Page 46: ...ICE BDE T7 COM Express Module Page 36 Chapter 5 5 BIOS...
Page 81: ...ICE BDE T7 COM Express Module Page 71 6 Software Drivers Chapter 6...
Page 83: ...ICE BDE T7 COM Express Module Page 73 Appendix A A Regulatory Compliance...
Page 85: ...ICE BDE T7 COM Express Module Page 75 B Product Disposal Appendix B...
Page 87: ...ICE BDE T7 COM Express Module Page 77 Appendix C C BIOS Options...
Page 90: ...ICE BDE T7 COM Express Module Page 80 Appendix D D Digital I O Interface...
Page 93: ...ICE BDE T7 COM Express Module Page 83 Appendix E E Watchdog Timer...
Page 96: ...ICE BDE T7 COM Express Module Page 86 Appendix F F Hazardous Materials Disclosure...
