System Installation
NANO-8045 User’s Manual
3-4
3.4.4 Audio
Controller
Please find Realtek ALC262 Audio driver form NANO-8045 CD-title.
The drivers
support Windows XP / VISTA.
3.5 WDT
Function
The algorithm of the WDT function can be simply described as a timer counting
process with an output event. The Time-Out period ( T
wd
) can be set by software
commands or hardware jumpers that depend on the board circuit design and may be
different among the boards. This timer can be used to monitor a software hang.
Nano-8045 allows users to control WDT by issuing dynamic software commands.
The WDT starts counting when it is activated. It will cause a system reset once it
expires. Before WDT expires, a refreshing command with a T
wd
can be issued to
re-count WDT and continue the status monitoring. If the system encounters a
software or application hang , WDT will generate a system reset after its timeout.
The related Control Registers of WDT are included in the following programming
guide that is written in C language. User can write a non-zero value ( defined as T
wd
)
into the Time-out Value Register ( CR_T
wd
) to enable WDT. Users can write 0x00 and
then T
wd
to CR_T
wd
to refresh WDT. To refresh WDT, the time tolerance of refreshing
interval must be considered. The smaller of T
wd
, the more deviation of WDT and you
need to include more tolerance. “Let T
wd
be longer than 2 seconds” is the
recommendation due to the limitation of Winbond W83627DHG WDT. You can call
Portwell support center for reference. The value read back from CR_T
wd
indicates the
counting down value instead of the original T
wd
. System will be reset after the
Time-out Value to be counted down to zero. Users can directly fill a zero value into
CR_T
wd
to disable WDT immediately. To ensure a successful access to the desired
Control Register, the following programming guide should be followed.
Programming guide :
CR : Configuration Register.
LD : Logical Device of SIO . There are 11 LDs in W83627DHG SIO.
CR00~2F : Global Control Registers. ( All LDs share these CRs )
CR07 : LD selection.
CR30~FF : Each LD has its own CR30~FF.
