Pre-computation based ternary content addressable memory

摘要

A pre-computation based TCAM configured to reduce the number of match lines being pre-charged during a search operation to save power is disclosed. The pre-computation based TCAM stores additional information in a secondary TCAM that can be used to determine which match lines in a primary TCAM storing data words to be searched need not be pre-charged because they are associated with data words guaranteed to not match. The additional information stored in secondary TCAM can include a pre-computation word that represents a range inclusive of a lower and upper bound of a number of ones or zeroes possible in a corresponding data word stored in the primary TCAM.

主权项

1. A pre-computation based ternary content addressable memory (TCAM), comprising:
a primary TCAM comprising a match line associated with a data word in the primary TCAM; and a secondary TCAM comprising a match line associated with a pre-computation word in the secondary TCAM, wherein the pre-computation word represents a range inclusive of a lower bound of a number of ones or zeros possible in the data word and an upper bound of the number of ones or zeros possible in the data word, and wherein the match line associated with the pre-computation word in the secondary TCAM is configured to disable pre-charging of the match line associated with the data word in the primary TCAM.