A reconfigurable content addressable memory

A 256 word by 64 b reconfigurable content addressable memory (RCAM) that can be written, searched, or read with a 100 ns cycle time is described. Designed for general high-speed table lookup applications, the RCAM has self-test and reconfiguration features to simplify testing and improve yield. For more than 256 words, the RCAM has extension logic built into the word-finding logic. In a multichip application, all pins of each RCAM are tied together, except for the F-line pins (Fi, Fo, and Fd). The F pins ensure that only one chip writes onto the data bus and only one chip stores a word. The Fi, Fo, and Fd are analogous to the carry in, carry propagate, and carry generate signals of a carry look ahead adder