The P89V664 has an abnormal watchdog behaviour:
1) Enable watchdog -> ok
2) Serve the watchdog -> ok
3) Don't serve the watchdog:
- Reset condition is detected (5us high on RST @18MHz)
- Device does NOT continue with RESTART user-program (abnormal behaviour), and does also not continue the program in the main loop (which is expected because the reset condition was given)

Remarks:
- User program works properly on P89C664
- Yes, I know the migration-sheet from Kees
- ALE has pull-up-resistor
- VDD is ok
- Error can be observe every time and on multiple devices

Any solutions?

Best regards, Claus