Portwell ROBO-8712VLA, User Manual

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System Installation
ROBO-8712VLA User’s Manual 3-5
3.5 Clear CMOS Operation
The following table indicates how to enable/disable CMOS Clear Function hardware
circuit by putting jumpers at proper position.
JP1 Function
1-2 Short Normal Operation
★
2-3 Short Clear CMOS contents
To correctly operate CMOS Clear function, users must turn off the system, move JP1
jumper to short pin 2 and 3. To clear CMOS contents, please turn the power back on
and turn it off again for AT system, or press the toggle switch a few times for ATX
system. Move the JP1 back to 1-2 position (Normal Operation) and start the system.
System will then produce a “CMOS Check Sum Error” message and hold up. Users
may then follow the displayed message to load BIOS default setting.
3.6 WDT Function
The working algorithm of the WDT function can be simply described as a counting
process. The Time-Out Interval can be set through software programming. The
availability of the time-out interval settings by software or hardware varies from
boards to boards.
ROBO-8712VLA allows users control WDT through dynamic software
programming. The WDT starts counting when it is activated. It sends out a signal to
system reset or to non-maskable interrupt (NMI), when time-out interval ends. To
prevent the time-out interval from running out, a re-trigger signal will need to be
sent before the counting reaches its end. This action will restart the counting process.
A well-written WDT program should keep the counting process running under
normal condition. WDT should never generate a system reset or NMI signal unless
the system runs into troubles.
The related Control Registers of WDT are all included in the following sample
program that is written in C language. User can fill a non-zero value into the Time-
out Value
Register to enable/refresh WDT. System will be reset after the Time-out
Value to be counted down to zero. Or user can directly fill a zero value into Time-out
Value Register to disable WDT immediately. To ensure a successful accessing to the
content of desired Control Register, the sequence of following program codes should
be step-by-step run again when each register is accessed.
Additionally, there are maximum 2 seconds of counting tolerance that should be
considered into user’ application program. For more information about WDT, please
refer to Winbond W83627HF data sheet.