I specified "Number of paths per endpoint" to be 1 while running TimeAhead from PlanAhead, but I see 2 paths for each endpoint in results; for example, for ps0_0 a path from action/Q and another one from int_0/Q is being reported.
Why does this happen?
This is the intended behavior for timing analysis in planAhead. An endpoint in planAhead is a pin, not an instance. In this case, the two paths ending at ps0_0 are two different pins. One is to the CE pin, and the other is to the D pin.