Synonym hit RAM - a 500-MHz CMOS SRAM macro with 576-bit parallel comparison and parity check functions

A 1.5-ns-access 500-MHz synonym hit RAM has been developed using 0.25-/spl mu/m CMOS technology, which is the macro-cell to be used in microprocessor chips. We have proposed a virtual cache system with a synonym hit RAM, which achieves both high speed and large capacity because it solves the synonym problem that occurs with large-capacity cache systems. In this system, the RAM macro needs 576-bit parallel comparison and parity check functions. The configuration used achieves testability and low-power dissipation of large 576-bit data output. Moreover, the dynamic-NOR with a dynamic-inverter and sense-amplifier activation pulse generator are essential for reducing the comparison delay.