The MCA implements a watchdog timer in its firmware. Both internal CPU watchdog timers on the ConnectCore 8X are disabled by default because the MCA is responsible for the power/reset initialization of the SOM as a whole.

Features

You can configure the following MCA watchdog features:

  • Set the timeout to a value between 1 and 255 seconds.

  • Initiate interrupt or system reset.

  • Initiate full-system reset (including the MCA itself) or CPU-only reset.

Kernel configuration

You can manage the MCA watchdog driver support through the following kernel configuration option:

  • Digi ConnectCore SOMs Micro Controller Assist Watchdog (CONFIG_MCA_WATCHDOG)

This option is enabled as built-in on the default ConnectCore 8X kernel configuration file.

Kernel driver

The MCA watchdog driver is located at:

File Description

drivers/watchdog/mca_wdt.c

MCA watchdog driver

Device tree bindings and customization

The MCA watchdog device tree binding is documented at Documentation/devicetree/bindings/watchdog/digi,mca-wdt.txt.

Watchdog inside the MCA

ConnectCore 8X device tree
mca_{mca-dev-name}: mca@63 {

	...

	watchdog {
		compatible = "digi,mca-{mca-dev-name}-wdt";
		digi,full-reset;
	};
};

Using the watchdog

You can access the watchdog from your Android application. See Watchdog API for more information about the watchdog APIx.

Sample application

The Watchdog Sample Application demonstrates the usage of the Watchdog API. The sample allows you to interact with the watchdog service by registering the application either to the system or the application watchdog services and report application failure at any time.

Go to GitHub to see the application instructions and source code.