Interface circuit for coupling between logic circuit domains

摘要

CMOS circuitry is partitioned into first and second logic circuit domains. The first logic circuit domain may be optionally a cuttable domains (C_Domains) where circuitry has power supply gating to reduce leakage power and non-cuttable domains (NC_Domains) where circuitry does not have power supply gating. Each output that couples signals from one logic circuit domain to another logic circuit is interfaced with a C_driver and a S_keeper which automatically assure that the output state is held when circuitry is power-gated put to reduce leakage power. The S_keeper and C_driver have low leakage circuits that maintain signal states and are not used for high speed operation.