US Patent 7484187 Clock-gating through data independent logic

Given a function F of a circuit having a data latching device and a feedback loop feeding an output Q of the device into logic which feeds the device, a method includes extracting at least one data independent case and clock-gating the device with the at least one data independent case. The method also includes eliminating the feedback loop if function F depends only on Q with a positive polarity or leaving the feedback loop if function F depends on Q in both positive and negative polarities.