Integrated circuit with multi-bit clock gating cells

Abstract

A multi-bit clock gating cell is used in an integrated circuit (IC) in place of single bit clock gating cells to reduce power consumption. A physical design method is used to form a clock tree of the IC. Initial positions of clock gating cells are defined with respective initial clock input paths. Selected clock gating cells are moved to modified positions in which they may be adjoining. Adjoining cells are merged by substituting a multi-bit clock gating cell having multiple gating signal inputs, corresponding gated clock outputs, and a common clock input path. A net reduction is obtained for the overall capacitance of the clock path due to reduction of the upstream capacitance of the clock path and of the resulting multi-bit clock gating cell itself, compared with the aggregate capacitance of the clock paths of the corresponding clock gating cells before moving and merging.