IVS-200-ULT2 Embedded System
Page 100
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.
Содержание IVS-200-ULT2
Страница 13: ...IVS 200 ULT2 Embedded System Page 1 Chapter 1 1 Introduction ...
Страница 22: ...IVS 200 ULT2 Embedded System Page 10 Chapter 2 2 Unpacking ...
Страница 25: ...IVS 200 ULT2 Embedded System Page 13 VESA MIS D 100 wall mount kit Table 2 2 Optional Items ...
Страница 26: ...IVS 200 ULT2 Embedded System Page 14 Chapter 3 3 Installation ...
Страница 50: ...IVS 200 ULT2 Embedded System Page 38 Chapter 4 4 BIOS ...
Страница 85: ...IVS 200 ULT2 Embedded System Page 73 Chapter 5 5 Troubleshooting and Maintenance ...
Страница 90: ...IVS 200 ULT2 Embedded System Page 78 Chapter 6 6 Interface Connectors ...
Страница 97: ...IVS 200 ULT2 Embedded System Page 85 Appendix A A Regulatory Compliance ...
Страница 102: ...IVS 200 ULT2 Embedded System Page 90 B Safety Precautions Appendix B ...
Страница 108: ...IVS 200 ULT2 Embedded System Page 96 Appendix C C BIOS Menu Options ...
Страница 111: ...IVS 200 ULT2 Embedded System Page 99 Appendix D D Watchdog Timer ...
Страница 114: ...IVS 200 ULT2 Embedded System Page 102 Appendix E E Hazardous Materials Disclosure ...