UPC-12A/GM45 Panel PC
Page 128
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 UPC-12A/GM45
Page 13: ...UPC 12A GM45 Panel PC Page 1 1 Introduction Chapter 1 ...
Page 24: ...UPC 12A GM45 Panel PC Page 12 2 Detailed Specifications Chapter 2 ...
Page 39: ...UPC 12A GM45 Panel PC Page 27 3 Unpacking Chapter 3 ...
Page 43: ...UPC 12A GM45 Panel PC Page 31 4 Installation Chapter 4 ...
Page 68: ...UPC 12A GM45 Panel PC Page 56 5 System Maintenance Chapter 5 ...
Page 76: ...UPC 12A GM45 Panel PC Page 64 6 AMI BIOS Setup Chapter 6 ...
Page 111: ...UPC 12A GM45 Panel PC Page 99 7 Battery Monitoring and Remote Control Chapter 7 ...
Page 127: ...UPC 12A GM45 Panel PC Page 115 A External Connector Pinouts Appendix A ...
Page 131: ...UPC 12A GM45 Panel PC Page 119 B Safety Precautions Appendix B ...
Page 136: ...UPC 12A GM45 Panel PC Page 124 C BIOS Configuration Options Appendix C ...
Page 139: ...UPC 12A GM45 Panel PC Page 127 D Watchdog Timer Appendix D ...
Page 142: ...UPC 12A GM45 Panel PC Page 130 E Hazardous Materials Disclosure Appendix E ...