TCS Embedded Software Engineer interview questions

Embedded C questions: difference between structure and Union, structure padding, pointer, pointer types, NULL pointer uses, function pointer, volatile vs constant? constant vs macros? program: reverse a number in an array? Controller related questions: little endian, big endian, difference, ISR, Interrupt latency, how to minimize interrupt latency, I2C, I2C in multimaster, clock stretching, CAN frame, arbitration in CAN, CAN transceiver uses, if std CAN and extended CAN has same address who will win the race for arbitration