Datasheet

99
8068U–AVR–06/2013
XMEGA A3
Not recommended for new designs -
Use XMEGA A3U series
26. WDR instruction inside closed window will not issue reset
When a WDR instruction is execute within one ULP clock cycle after updating the window
control register, the counter can be cleared without giving a system reset.
Problem fix/Workaround
Wait at least one ULP clock cycle before executing a WDR instruction.