Associative memory with fully parallel nearest-manhattan-distance search for low-power real-time single-chip applications

A fully-paralled minimum Manhattan-distance search associative memory has been designed in 0.35μm CMOS with 3-metal layers. The nearest-match unit consumes only 1.02mm², while the chip area is 7.49mm². The measured winner-search time of this chip, the time to determine the best-matching reference-data word for an input-data word among a database of 128 reference words (5-bit, 16 units), is < 180nsec. This corresponds to a performance requirement of 16 GOPS/mm², if a 32-bit computer with the same chip area would have to run the same workload. Furthermore the power dissipation of the designed test chip is only about 26.7mW/mm².