Apple Inc.
No-enable setup clock gater based on pulse

Abstract:

Systems, apparatuses, and methods for implementing a high-performance clock-gating circuit are described. A first pull-down stack receives enable and pulse signals on gates of N-type transistors which pull down an output node when the enable and pulse signals are both high. A pull-up transistor coupled to the output node receives a clock signal which turns off the pull-up transistor when the clock signal is high. A first pull-up stack receives the inverted pulse signal and the enable signal on gates of P-type transistors to cause the output node to be high when the enable signal and inverted pulse signal are low. A second pull-up stack maintains a high voltage on the output node after the pulse event has ended but while the clock signal is still high. A second pull-down stack maintains a low voltage on the output node after the pulse event but while the clock remains high.