General Description: An error may be generated by PAR when timing constraints are too strict. The error is:
Error: baspw:97 PAR: Not all timing constraints could be satisfied.
This occurs when the logic delays are greater than the timing constraints. PAR tries to Place and Route the design in such a way that it can meet the timing constraints. However, when the delays through the logic are greater than the constraint on the logic (too many levels of logic or too tight of a constraint), PAR realizes that the logic delays (pre-route) exceed the constraints and stops. This is to save time since there is no possible way to meet the constraints.
Workaround: Increase the timing constraint or reduce the levels of logic.