Information

Section Number Title Page
Chapter 23
Watchdog Timer (WDOG)
23.1 Introduction...................................................................................................................................................................407
23.2 Features.........................................................................................................................................................................407
23.3 Functional overview......................................................................................................................................................409
23.3.1 Unlocking and updating the watchdog.........................................................................................................410
23.3.2 Watchdog configuration time (WCT)..........................................................................................................411
23.3.3 Refreshing the watchdog..............................................................................................................................412
23.3.4 Windowed mode of operation......................................................................................................................412
23.3.5 Watchdog disabled mode of operation.........................................................................................................412
23.3.6 Low-power modes of operation...................................................................................................................413
23.3.7 Debug modes of operation...........................................................................................................................413
23.4 Testing the watchdog....................................................................................................................................................414
23.4.1 Quick test.....................................................................................................................................................414
23.4.2 Byte test........................................................................................................................................................415
23.5 Backup reset generator..................................................................................................................................................416
23.6 Generated resets and interrupts.....................................................................................................................................416
23.7 Memory map and register definition.............................................................................................................................417
23.7.1 Watchdog Status and Control Register High (WDOG_STCTRLH)...........................................................418
23.7.2 Watchdog Status and Control Register Low (WDOG_STCTRLL)............................................................420
23.7.3 Watchdog Time-out Value Register High (WDOG_TOVALH).................................................................420
23.7.4 Watchdog Time-out Value Register Low (WDOG_TOVALL)..................................................................421
23.7.5 Watchdog Window Register High (WDOG_WINH)..................................................................................421
23.7.6 Watchdog Window Register Low (WDOG_WINL)...................................................................................422
23.7.7 Watchdog Refresh register (WDOG_REFRESH).......................................................................................422
23.7.8 Watchdog Unlock register (WDOG_UNLOCK).........................................................................................423
23.7.9 Watchdog Timer Output Register High (WDOG_TMROUTH).................................................................423
23.7.10 Watchdog Timer Output Register Low (WDOG_TMROUTL)..................................................................423
23.7.11 Watchdog Reset Count register (WDOG_RSTCNT)..................................................................................424
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 17