First round is the written test, i took digital design but you have a choice of taking analog and so on.. you get questions ranging from basic digital electronics to vlsi and hdl, with general course questions as well in the mix.. its like an all round electronics paper with a bias towards digital design. you also have a general aptitude paper which you should be able to answer without too much preparation. apply your knowledge and you would be able to get through this round easily.
the next is the tech round, where they take a look at your resume and ask about your projects, then move onto looking at your thinking process behind a few of your test answers (i guess to eliminate the chance of you fluking through), and if you answered your paper with fair confidence you shouldnt have a problem. the interviewer mentioned in my case that my tech answers were average but my aptitude was very high which is why i was so high on their list..
The third round is a "casual" hr round, you are asked about your plans for the future, what your parents do for a living and so on. no issues here at all.