Power savings in a content addressable memory device using masked pre-compare operations

摘要

A CAM device for comparing a search key with a plurality of ternary words stored in a CAM array includes one or more population counters, a pre-compare memory, and a pre-compare circuit. The present embodiments reduce the power consumption of CAM devices during compare operations between a search key and ternary words stored in a CAM array by selectively enabling the match lines in the CAM array in response to pre-compare operations between a set of population counts corresponding to the masked search key and a set of population counts corresponding to the ternary words stored in the CAM array.

主权项

1. A content addressable memory (CAM) device, comprising:
a CAM array having a plurality of rows of CAM cells, each row of the plurality of rows storing an associated word and being coupled to a corresponding match line; and a pre-compare circuit, coupled to the CAM array, configured to compare a first data population count with a first key population count and a second data population count with a second key population count to determine whether a search key can match the associated word stored in each row of the plurality of rows.