So basically 1st round is aptitude + digital + programming (in return format).
Atitude - logical reasoning, quantitative aptitude. (Average finding, probability) Kind of questions
Digital - half adder, truth table, demultiplexer, Boolean equations, Transistor, D-flipflop. (Read everything with its application and principal)
Programing - we can use any programming language to slove the problem.
1. Printing only the even numbers. N=32.
2. Finding ambiguity .
3 . Which is based on looping concept.
You have to be strong in these 3 areas so then you'll be able to clear the interview.
Hoping that it's helpful.