WSB-G41A CPU Card
Page 103
NOTE:
The following discussion applies to DOS. Contact IEI support or visit the IEI
website for drivers for other operating systems.
The Watchdog Timer is a hardware-based timer that attempts to restart the system when it
stops working. The system may stop working because of external EMI or software bugs.
The Watchdog Timer ensures that standalone systems like ATMs will automatically
attempt to restart in the case of system problems.
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 C-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.
Содержание WSB-G41A-R11
Страница 11: ...WSB G41A CPU Card Page xi Table 5 1 BIOS Navigation Keys 60...
Страница 13: ...WSB G41A CPU Card Page 1 Chapter 1 1 Introduction...
Страница 21: ...WSB G41A CPU Card Page 9 Chapter 2 2 Packing List...
Страница 26: ...WSB G41A CPU Card Page 14 Chapter 3 3 Connectors...
Страница 47: ...WSB G41A CPU Card Page 35 Chapter 4 4 Installation...
Страница 70: ...WSB G41A CPU Card Page 58 Chapter 5 5 BIOS...
Страница 107: ...WSB G41A CPU Card Page 95 Appendix A A BIOS Options...
Страница 110: ...WSB G41A CPU Card Page 98 Appendix B B Terminology...
Страница 114: ...WSB G41A CPU Card Page 102 Appendix C C Watchdog Timer...
Страница 117: ...WSB G41A CPU Card Page 105 Appendix D D Digital I O Interface...
Страница 119: ...WSB G41A CPU Card Page 107 Appendix E E Hazardous Materials Disclosure...