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MPU subsystem. If the interrupt is not serviced by software before a second timeout occurs, the timer
generates a reset request.
If a restart occurs at the same time the watchdog counter reaches zero, an interrupt is not generated.
Related Information
•
on page 24-3
•
Setting the Timeout Period Values
on page 24-4
•
Selecting the Output Response Mode
on page 24-4
•
on page 24-4
Watchdog Timer Pause Mode
The watchdog timers can be paused during debugging. Pausing the watchdog timers is controlled by the
system manager. The following options are available:
• Pause the timer while either CPU0 or CPU1 is in debug mode
• Pause the timer while only CPU1 is in debug mode
• Pause the timer while only CPU0 is in debug mode
• Do not pause the timer
When pause mode is enabled, the system manager pauses the watchdog timer while debugging. When pause
mode is disabled, the watchdog timer runs even while debugging.
When the system manager exits reset, the watchdog pausing feature is enabled for both CPUs by default.
Related Information
on page 24-4
Watchdog Timer Clocks
Each watchdog timer is connected to the
osc1_clk
clock so that timer operation is not dependent on the
phase-locked loops (PLLs) in the clock manager. This independence allows recovery from software that
inadvertently programs the PLLs in the clock manager incorrectly.
Related Information
on page 2-1
For more information, refer to the
Clock Manager
chapter.
Watchdog Timer Resets
Watchdog timers are reset by a cold or warm reset from the reset manager, and are disabled when exiting
reset. †
Related Information
on page 3-1
For more information, refer to the
Reset Manager
chapter.
Altera Corporation
Watchdog Timer
24-3
Watchdog Timer Pause Mode
cv_54024
2013.12.30