PPC-F12B/15B/17B-BTi Panel PC
Page 121
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-F12B-BTi
Page 14: ......
Page 15: ...PPC F12B 15B 17B BTi Panel PC Page 1 1 Introduction Chapter 1...
Page 20: ...PPC F12B 15B 17B BTi Panel PC Page 6 Figure 1 5 PPC F15B F17B BTi Bottom View...
Page 26: ...PPC F12B 15B 17B BTi Panel PC Page 12 2 Unpacking Chapter 2...
Page 30: ...PPC F12B 15B 17B BTi Panel PC Page 16 3 Installation Chapter 3...
Page 62: ...PPC F12B 15B 17B BTi Panel PC Page 48 Chapter 4 4 System Maintenance...
Page 64: ...PPC F12B 15B 17B BTi Panel PC Page 50 5 BIOS Setup Chapter 5...
Page 101: ...PPC F12B 15B 17B BTi Panel PC Page 87 6 Interface Connectors Chapter 6...
Page 121: ...PPC F12B 15B 17B BTi Panel PC Page 107 Appendix A A Regulatory Compliance...
Page 126: ...PPC F12B 15B 17B BTi Panel PC Page 112 B BIOS Configuration Options Appendix B...
Page 129: ...PPC F12B 15B 17B BTi Panel PC Page 115 C Safety Precautions Appendix C...
Page 134: ...PPC F12B 15B 17B BTi Panel PC Page 120 D Watchdog Timer Appendix D...
Page 137: ...PPC F12B 15B 17B BTi Panel PC Page 123 E Hazardous Materials Disclosure Appendix E...