Watchdog timer – ADLINK nanoX-TCR User Manual

Page 32

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Chapter 3

Hardware

28

Reference Manual

nanoX-TCR

Watchdog Timer

The Watchdog Timer (WDT) restarts the system if a mishap occurs, ensuring proper start-up after the

interruption. Possible problems include failure to boot properly, the application software’s loss of control,
failure of an interface device, unexpected conditions on the bus, or other hardware or software malfunctions.

Use the ADLINK Intelligent Device Interface (AIDI) Library to configure the WDT interface. AIDI driver

information is available in the Utilities link of the nanoX-TCR product page at:

http://www.adlinktech.com

.

An AIDI demo program and the AIDI User’s Manual showing how to use the WDT function also reside in

the Utilities link of the nanoX-TCR product page.

The WDT (Watchdog Timer) can be used both during the boot process and during normal system operation.

During the Boot process – If the OS fails to boot in the time interval set in the AIDI Library, the system
will reset.
Enable the WDT as described in the AIDI Library User’s guide. Set the WDT for a time-out interval in
seconds, between 1 and 255, in one second increments. Ensure you allow enough time for the boot

process to complete and for the OS to boot. The OS or application must tickle the WDT as soon as it

comes up.

During System Operation – The user can set up the WDT hardware by accessing the hardware directly
using the AIDI Library. The system must tickle the WDT in the time set when the WDT is initialized or

the system will be reset.

Watchdog Code example – ADLINK provides a source code example (AIDI demo program) in the
Utilities link of the nanoX-TCR product page illustrating how to control the WDT. The code example
can be easily copied to your development environment to compile and test or make any desired changes

before compiling.

A98

SER0_TX

B98

DDI0_CTRLCLK_AUX+
(SDVO Control Clock)

A99

SER0_RX

B99

DDI0_CTRLDATA_AUX-
(SDVO Control Data)

A100

GND

B100

GND

A101

SER1_TX

B101

FAN_PWMOUT (Fan Speed Control)

A102

SER1_RX

B102

FAN_TACHIN (Fan Tachometer -

PU 10k 3.3V)

A103

LID# (ACPI type LID Switch -

PU 10k 3.3V S5 Standby)

B103

SLEEP# (GPIO4 of PCH -

PU 10k 3.3V S5
Standby)

A104

VCC_12V

B104

VCC_12V

A105

VCC_12V

B105

VCC_12V

A106

VCC_12V

B106

VCC_12V

A107

VCC_12V

B107

VCC_12V

A108

VCC_12V

B108

VCC_12V

A109

VCC_12V

B109

VCC_12V

A110

GND

B110

GND

Table 3-5. COM Express A-B Connector Signal Descriptions (Continued)

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