Why is the SPC56EL, MPC564L DualCore controller in Lockstep mode hanging in SAFE mode when running without UDE ?

That happens typically when some registers are not initialized before using, e.g. the 64 bit general purpose register for spe instructions. after reset these registers will have random content on both cores. if that register are used that could result in different results on both cores which will raise a lockstep error.

To avoid such problems do an initialization off all registers and CPU resources before using.