Are S/R flip flops still relevent in digital design?
SR flip-flops are still useful in constructing asynchronous sequential logic circuits. Normal clocked flip-flops internally are just of that kind. Complex sequential circuits are at least on paper possible to construct using SR flip-flops, but designers generally use clocked flip-flops to keep the gate and transmission delays out of the major role. Complex sequential logic simply is much more easy to design and test if all state changes happen as clocked.