We are using MPC5774P together with System Basis Chip MC33907/08. At ECU power-up we would like to have the external watchdog in MC33907/08 disabled as long as we are running in the bootloader. Then, when we enter the application SW the watchdog window is set to an appropriate size.
We are using the following sequence in bootloader SW:
1. After power on reset the INIT FS phase is started. This phase is active until first watchdog kick or timeout after 256 ms.
2. Watchdog registers in SBC are initialized, including watchdog disabling by setting watchdog window size to 0 ms.
3. One watchdog refresh is sent from 5744P -> Exit of INIT FS state.
Is this sequence correct?