The NXP PNX8330 processor Configuration unit
supports three timers, one of which will act as a watchdog device.
Once the timer is started it will automatically reset the processor
unless software resets the timer at regular intervals. The package
CYGPKG_DEVS_WATCHDOG_MIPS_PNX8330 provides an eCos
driver for this device, complementing the generic package
CYGPKG_IO_WATCHDOG. The functionality should be
accessed via the standard eCos watchdog functions
The hardware, and thus the watchdog driver, only supports reset mode.
The PNX8330 watchdog driver package should be loaded automatically
when selecting a platform containing a PNX8330 processor, and it
should never be necessary to load it explicitly into the
configuration. The package is inactive unless the generic watchdog
CYGPKG_IO_WATCHDOG is loaded. Depending on
the choice of eCos template it may be necessary to load the latter.
The package provides two main configuration options.
CYGIMP_WATCHDOG_HARDWARE can be used to disable the
use of the hardware watchdog and switch to a software emulation
provided by the generic watchdog package instead. This may prove
useful during debugging.
determines the timeout before the hardware watchdog resets the system.
The default setting gives a 10-second timeout. The maximum timeout is
determined by the CPU clock frequency, approximately 70 seconds for a
The watchdog device driver does not require any platform-specific
support. The only porting effort required is to list
CYGPKG_DEVS_WATCHDOG_MIPS_PNX8330 as one of the hardware
packages in the ecos.db target entry.