EP-265-910/EP-267-910 Enrich POS System
Page 123
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 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. 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 EP-265-910
Page 1: ...EP 265 910 EP 267 910 Enrich POS System Page i EP 265 910 EP 267 910 Enrich POS System ...
Page 15: ...EP 265 910 EP 267 910 Enrich POS System Page 1 1 Introduction Chapter 1 ...
Page 26: ...E 265 910 EP 267 910 Enrich POS System Page 12 2 Detailed Specifications Chapter 2 ...
Page 41: ...EP 265 910 EP 267 910 Enrich POS System Page 27 3 Unpacking Chapter 3 ...
Page 44: ...E 265 910 EP 267 910 Enrich POS System Page 30 4 Installation Chapter 4 ...
Page 66: ...E 265 910 EP 267 910 Enrich POS System Page 52 5 System Maintenance Chapter 4 ...
Page 72: ...E 265 910 EP 267 910 Enrich POS System Page 58 6 AMI BIOS Setup Chapter 6 ...
Page 116: ...E 265 910 EP 267 910 Enrich POS System Page 102 7 System Monitoring Chapter 7 ...
Page 119: ...EP 265 910 EP 267 910 Enrich POS System Page 105 A System Specifications Appendix A ...
Page 125: ...EP 265 910 EP 267 910 Enrich POS System Page 111 B External Connector Pinouts Appendix B ...
Page 128: ...E 265 910 EP 267 910 Enrich POS System Page 114 C Safety Precautions Appendix C ...
Page 132: ...E 265 910 EP 267 910 Enrich POS System Page 118 D BIOS Configuration Options Appendix D ...
Page 136: ...E 265 910 EP 267 910 Enrich POS System Page 122 E Watchdog Timer Appendix E ...
Page 139: ...EP 265 910 EP 267 910 Enrich POS System Page 125 F Hazardous Materials Disclosure Appendix F ...
Page 143: ...EP 265 910 EP 267 910 Enrich POS System Page 129 G Index ...