Multi-Source CTS enabled with Structured “H” at upper sections of clock trees have always been ideal to deal with OCV and cross corner scaling in FinFet era. But with complex and complicated floorplan aspect ratios, uneven distribution of sinks, coupled with placement and routing restrictions, benefits of a classic H-tree at the toplevel is often subdued and restrained . Flexible H-Tree feature provides electrically symmetric buffering and balanced wire length benefits of an H-tree, but relaxes the requirement to be geometrically symmetric, enabling automated construction and synthesis