There were 2 interview stages.

The first interview was a phone interview and the second interview was onset.

I went quickly through my CV and they got to know me. I answered some technical questions and had a chance at the end to ask questions about their company.

First stage a phone interview. Asked about bit set and bit clear in an unsigned integer. Volatile and static in C.

Second stage was an onset. Asked me questions about what is DMA. To identify some peripherals, memory units such as RAM and CPU. Address bus and data bus. At the end of the interview had to do a test in C.