WAFER-CV-D25501/N26001 3.5" SBC
Page 117
NOTE:
The following discussion applies to DOS environment. Contact IEI support
or visit the IEI website for specific drivers for other operating systems.
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 EMIs 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 E-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.
Summary of Contents for WAFER-CV-N26001
Page 11: ...WAFER CV D25501 N26001 3 5 SBC Page xi Figure 6 18 Audio Driver Installation Complete 103...
Page 15: ...WAFER CV D25501 N26001 3 5 SBC Page 1 Chapter 1 1 Introduction...
Page 19: ...WAFER CV D25501 N26001 3 5 SBC Page 5 Figure 1 3 WAFER CV D25501 N26001 Dimensions mm...
Page 23: ...WAFER CV D25501 N26001 3 5 SBC Page 9 Chapter 2 2 Packing List...
Page 27: ...WAFER CV D25501 N26001 3 5 SBC Page 13 Chapter 3 3 Connectors...
Page 52: ...WAFER CV D25501 N26001 3 5 SBC Page 38 Chapter 4 4 Installation...
Page 75: ...WAFER CV D25501 N26001 3 5 SBC Page 61 Chapter 5 5 BIOS...
Page 103: ...WAFER CV D25501 N26001 3 5 SBC Page 89 6 Software Drivers Chapter 6...
Page 118: ...WAFER CV D25501 N26001 3 5 SBC Page 104 Appendix A A Regulatory Compliance...
Page 120: ...WAFER CV D25501 N26001 3 5 SBC Page 106 Appendix B B BIOS Options...
Page 123: ...WAFER CV D25501 N26001 3 5 SBC Page 109 Appendix C C Terminology...
Page 127: ...WAFER CV D25501 N26001 3 5 SBC Page 113 Appendix D D Digital I O Interface...
Page 130: ...WAFER CV D25501 N26001 3 5 SBC Page 116 Appendix E E Watchdog Timer...
Page 133: ...WAFER CV D25501 N26001 3 5 SBC Page 119 Appendix F F Hazardous Materials Disclosure...
