AFL-HM55 Series Panel PC
Page 124
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, the 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 AFL-HM55
Страница 12: ...AFL HM55 Series Panel PC Page I 1 Introduction Chapter 1 ...
Страница 23: ...AFL HM55 Series Panel PC Page 12 2 Unpacking Chapter 2 ...
Страница 29: ...AFL HM55 Series Panel PC Page 18 3 Installation Chapter 3 ...
Страница 63: ...AFL HM55 Series Panel PC Page 52 Point of Sale POS Advertising terminal ...
Страница 64: ...AFL HM55 Series Panel PC Page 53 4 System Maintenance Chapter 4 ...
Страница 70: ...AFL HM55 Series Panel PC Page 59 5 BIOS Setup Chapter 5 ...
Страница 96: ...AFL HM55 Series Panel PC Page 85 6 Software Drivers Chapter 6 ...
Страница 123: ...AFL HM55 Series Panel PC Page 112 A Safety Precautions Appendix A ...
Страница 127: ...AFL HM55 Series Panel PC Page 116 Appendix B B ALC892 Digital Microphone Configuration ...
Страница 131: ...AFL HM55 Series Panel PC Page 120 C BIOS Configuration Options Appendix C ...
Страница 134: ...AFL HM55 Series Panel PC Page 123 D Watchdog Timer Appendix D ...
Страница 137: ...AFL HM55 Series Panel PC Page 126 E Hazardous Materials Disclosure Appendix E ...