It can happen at any stage where transistors are involved. So for important thing just ecc memory is not enough, I saw a video where newer space craft basically have a voting system, so 3 or 4 subsystem calculating exact same instructions, and the "majority" wins.
Fun fact! We actually do this voting system with nuclear power PLC's in my industry. This sort of redundancy is used in all sorts of safety controllers
It can happen at any stage where transistors are involved. So for important thing just ecc memory is not enough, I saw a video where newer space craft basically have a voting system, so 3 or 4 subsystem calculating exact same instructions, and the "majority" wins.
Fun fact! We actually do this voting system with nuclear power PLC's in my industry. This sort of redundancy is used in all sorts of safety controllers