ECN-360A-HM65 Em b e d d e d S ys te m
P a g e 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 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 S u b -fu n c tio n :
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.
Содержание ECN-360A-HM65
Страница 8: ...ECN 360A HM65 Embedded Sys tem Page viii ROHS COMPLIANT UNDER 2002 95 EC WITHOUT MERCURY 139...
Страница 14: ...ECN 360A HM65 Embedded Sys tem Page 1 Chapter 1 1 Introduction...
Страница 19: ...ECN 360A HM65 Embedded Sys tem Page 6 Figure 1 3 ECN 360A HM65 Rear Panel...
Страница 21: ...ECN 360A HM65 Embedded Sys tem Page 8 Chapter 2 2 Unpacking...
Страница 25: ...ECN 360A HM65 Embedded Sys tem Page 12 Chapter 3 3 Ins tallation...
Страница 37: ...ECN 360A HM65 Embedded Sys tem Page 24 Chapter 4 4 Sys tem Motherboard...
Страница 68: ...ECN 360A HM65 Embedded Sys tem Page 55 Chapter 5 5 BIOS...
Страница 99: ...ECN 360A HM65 Embedded Sys tem Page 86 A Safety Precautions Appendix A...
Страница 104: ...ECN 360A HM65 Embedded Sys tem Page 91 B BIOS Menu Options Appendix B...
Страница 107: ...ECN 360A HM65 Embedded Sys tem Page 94 Appendix C C One Key Recovery...
Страница 115: ...ECN 360A HM65 Embedded Sys tem Page 102 Figure C 5 Partition Creation Commands...
Страница 148: ...ECN 360A HM65 Embedded Sys tem Page 135 D Watchdog Timer Appendix D...
Страница 151: ...ECN 360A HM65 Embedded Sys tem Page 138 Appendix E E Hazardous Materials Dis clos ure...