US Patent 7079407 Content addressable memory (CAM) device including match line sensing

A content addressable memory (CAM) device that includes a plurality of CAM cells coupled to a match line to affect a voltage of the match line in response to data values of the CAM cells and comparand data being in a predetermined logical relationship, and a match detect circuit coupled to the match line and adapted to differentially compare the voltage of the match line with a fixed reference voltage and, in response, generate an output signal having two or more logical states corresponding to the states of the predetermined logical relationship between the data value and the comparand data.