Abstract: Content-addressable memory (CAM) cells comprised of phase change material devices (PCMDs), including PCMD-based binary CAM cells (PCMD-based BCAM cells), PCMD-based ternary CAM cells (PCMD-based TCAM cells), and PCMD-based universal CAM cells (PCMD-based UCAM cells). The PCMDs of the various PCMD-based CAM cells are configured and programmed in a manner that allows a logic “0” or a logic “1” to be stored by the CAM cell. The logic value stored by a given PCMD-based CAM cell depends on the program states of the PCMDs. A program state of a PCMD is determined by whether the phase change material of the PCMD has been allowed to solidify to a crystalline, low-resistance state during a programming operation, or whether the phase change material of the PCMD is forced to solidify to an amorphous, high-resistance state during the programming operation.

Abstract: A content-addressable memory circuit includes a first local bit line coupled to a first memory location, a second local bit line coupled to a second memory location, a global bit line coupled to the first and second local bit lines and a global bit line accelerator coupled to the first and second local bit lines and the global bit line. The global bit line accelerator sets the second local bit line to a first logical value depending on a signal from the first local bit line. In this way, the global bit line accelerator accelerates the evaluation phase of operation of the second local bit line.

Abstract: In one embodiment, a CAM cell is provided that includes: an SRAM cell adapted to store a bit; a data line adapted to provide a corresponding comparand bit; an XOR gate adapted to XOR the stored bit and the comparand bit to provide an XOR output, and a switch adapted to close in response to the XOR output.