Arrived at the buildings, no other interview candidates and waited around 10 mins past scheduled time for the interview. Led to a small room and had 2 interviewers, one China and one UK. Both were pretty senior engineers. Was asked normal questions of why Arm, then almost immediately jumped straight into the technical questions

They had a list of questions to choose from and they randomly picked

First was about transistors and circuits - fairly straightforward.

Second was about the master slave relationship for writing a file

Third was how to draw a processor.

I found they kept asking stuff until you didn't know, to test the depth of your knowledge

Draw a diagram for a master-slave relationship for writing and reading to a file.