Functional Description
COMX-CAR-610 COM Express Carrier Board Installation and Use (6806800K26D
)
56
4.10 Watchdog Timer
The COMX-CAR-610 provides a watchdog timer (WDT), which is a combination of two
watchdog timers coming from COM Express connector and Super I/O.
A valid WDT output signal resets the COMX-CAR-610. The BIOS disables the device at boot
(software is enabled when the watchdog application loads). The WDT is disabled before
entering S3 state, and re-enabled upon exiting S3.
4.11 Real Time Clock (RTC)
There is an onboard SMT battery holder. The battery holder allows for the quick and easy
replacement of a 3 V button cell lithium battery which provides backup power to the onboard
RTC.
The RTC supports two lockable memory ranges. By setting bits in the configuration space, two
8-byte ranges can be locked to read and write accesses. This prevents unauthorized reading of
passwords or other system security information.
Figure 4-6
Watchdog Timer Block Diagram