I don't think there is a clear hard line where computer science ends and electrical engineering starts, as there is no clear hard line where CS ends and say mathematics starts.
CS by its nature is very interdisciplinary. CS.SE shares scope with many other sites: Math.SE, Crypto.SE, CompSci.SE, Stats.SE, etc. EE.SE is just one of these.
Computer architecture and logical circuits are clearly part of CS topics, they are part of ACM undergraduate curriculum, they are topics that computer scientists study, use, and do research on. I don't see why we need or would like to forbid questions in them on CS.SE (other than personal preference or interest in topics).
There are many sites that share scope and that is fine: different communities can have a different perspectives on the same question. The question is a CS question and can be answered by a computer scientist, so I think it is on-topic.
ps: as a reminder for people who have not followed previous meta discussions about scope, although we have many TCS question the scope of CS.SE is not just TCS, its scope is CS generally, including Computer Architecture, Software Engineering, Computer Networks, AI, Computer Security, etc.