PXD10RM Datasheet, PDF (122/1332 Pages) Freescale Semiconductor, Inc – PXD10 Microcontroller

period. If the service sequence is not written before the second consecutive time-out, the SWT generates
a system reset. The interrupt is indicated by the time-out interrupt flag (SWT_IR.TIF). The interrupt
request is cleared by writing a one to the SWT_IR.TIF bit.
The SWT_CO register shows the value of the down counter when the watchdog is disabled. When the
watchdog is enabled this register is cleared. The value shown in this register can lag behind the value in
the internal counter for up to six system plus eight counter clock cycles.
The SWT_CO can be used during a software self test of the SWT. For example, the SWT can be enabled
and not serviced for a fixed period of time less than the time-out value. Then the SWT can be disabled
(SWT_CR.WEN cleared) and the value of the SWT_CO read to determine if the internal down counter is
working properly.
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PXD10 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor