PPC-FxxC-Q370
Page 122
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 PPC-F C-Q370 Series
Page 17: ...PPC FxxC Q370 Page xvii BIOS Menu 31 Save Exit 87 ...
Page 18: ......
Page 19: ...PPC FxxC Q370 Page 1 Chapter 1 1 Introduction ...
Page 35: ...PPC FxxC Q370 Page 17 Chapter 2 2 Unpacking ...
Page 38: ...PPC FxxC Q370 Page 20 Chapter 3 3 Installation ...
Page 63: ...PPC FxxC Q370 Page 45 Chapter 4 4 BIOS ...
Page 106: ...PPC FxxC Q370 Page 88 Chapter 5 5 Troubleshooting and Maintenance ...
Page 110: ...PPC FxxC Q370 Page 92 6 Interface Connectors Chapter 6 ...
Page 125: ...PPC FxxC Q370 Page 107 Appendix A A Regulatory Compliance ...
Page 130: ...PPC FxxC Q370 Page 112 B Safety Precautions Appendix B ...
Page 136: ...PPC FxxC Q370 Page 118 Appendix C C BIOS Menu Options ...
Page 139: ...PPC FxxC Q370 Page 121 Appendix D D Watchdog Timer ...
Page 142: ...PPC FxxC Q370 Page 124 Appendix E E Error Beep Code ...
Page 144: ...PPC FxxC Q370 Page 126 Appendix F F Hazardous Materials Disclosure ...