Hello, I am debugging an issue where in power off, VDD_EXT is being held at ~0.8V (it is 1.8V normally) instead of going to 0V. We have a supervisor IC that is powered from a separate 1.8V rail. I suspect that somehow, one of the pins on the BF707 is being driven high, which is powering VDD_EXT through a protection diode.
My question: when VDD_EXT is not powered, must all pins in the VDD_EXT domain be undriven or held low? Are their any pins on the Blackfin that can not be driven high when their respective power domain is low?