Various embodiments of methods and systems for providing virtual leaf
driver nodes in a clock tree to drive a clock grid of an integrated
circuit are disclosed. An integrated circuit may include a large number
of clocked elements such as registers, flip-flops, etc. whose operation
is synchronized by one or more clocks. For example, an operation
performed by circuitry on one side of the die may need to occur at
precisely the same time as another operation performed by circuitry on
the other side of the die. In order to assure synchronicity of these
events, a clock grid may be provided in the IC that is driven by virtual
leaf driver nodes. The clock tree driving the clock grid may include a
tier of leaf buffers. The output of a leaf buffer may be split, and the
branches of the output connected to separate points on the clock grid.