A timing analysis for a PERIOD constraint reports "0 items analyzed." Why does this happen?
If a PERIOD constraint and a FROM:TO cover the same path, the PERIOD constraint is overridden. This conflict also occurs when using the OFFSET constraint with an associated PERIOD constraint and the FROM:TO constraint.
This causes the path to only be reported under the FROM:TO constraint. (The OFFSET and FROM:TO constraints perform similar analysis and normally only one of them is needed.)
This is correct behavior; the user needs to decide what type of constraint to use.
If you wish to use the PERIOD constraint, the solution is to remove the path from the FROM:TO or OFFSET constraint. This will allow the paths to be reported under the PERIOD constraint.