Documentation

Watchdog Timer

Watchdog timer (not recommended)

Description

On some units, you can program a watchdog to perform a system reboot when a programmable timeout occurs. The timeout interval can range from 1 to 255 seconds with one-second resolution, or from 1 to 255 minutes with one-minute resolution. When the timeout expires, an IRQ15 interrupt is asserted. With the Reboot upon expiration of watchdog parameter, you can specify that the system reboot at this time. At most, one block of this type can be included in a model.

Library

Simulink® Real-Time™ Library of Drivers No Longer Recommended for Use

Block Parameters

Timeout units

From the list, select either seconds or minutes. These are the units for the time.

Timeout interval

Enter a number between 1 and 255.

Show reset port (R)

Select this check box to display an input port labeled R. A signal connected to this port resets the watchdog whenever its value exceeds 0.5.

Reset upon keyboard activity

Select this check box to reset the watchdog whenever there is keyboard activity.

Reboot upon expiration of watchdog

Select this check box to reboot the unit when the watchdog timer expires. When the timeout expires, an IRQ15 interrupt is asserted, regardless of the state of this check box. If you choose not to reboot the system when the watchdog timer expires, you might want to write your own procedure to handle the IRQ15 assertion.

Sample time

Enter the base sample time or a multiple of the base sample time (-1 means sample time is inherited).

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