NVIDIA ASIC Digital Design Engineer interview questions

Intro and things worked on. Then he asked me deep about the project I was working on. Synchronous FIFO question. Wrote for 50 continuous cycle s in any 100 cycles but reading every alternate cycles. Depth reqd? How to design synch fifo ? How async fifo ? Is it possible to write and read from sync FIFO built using single port sram in same clock cycle ? Setup time and why we need it ? How will multiply by 63 ? Optimize way of finding the square of a number ? 1, 4, 9, 16, 25,