I am starting an app using Keil RTX on a Cortex-M3. The Cortex-M3 version of RTX uses the SysTick timer to generate the OS timer tick (there is no os_clock_demon). I need to use the Window Watchdog. It seems to me the place to put the update of the watchdog is in the system tick, but I don't see any hooks into this routine. Is it possible to add my update to the OS timer routine? Is there a better place to put it?