High-speed CAM-based architecture for a Prolog machine (ASCA)

A content addressable memory (CAM)-based machine architecture is proposed for a high-speed Prolog machine. This Prolog machine attempts to speed up the total Prolog execution performance by using a hierarchical pipelined scheme and a CAM-based backtracking scheme. The hierarchical pipelined scheme reduces the total number of Prolog execution steps to half of that using the conventional method. The CAM-based backtracking is efficiently and quickly achieved by using CAM´s sophisticated garbage collection function, which eliminates the need for stacks and additional operation cycles. In this machine, all Prolog execution can be simply controlled by a semantic information `inference depth´ without any address handling by storing all working information, binding and control information, in CAMs. This machine attains a performance of 100 KLIPS (kilo logical inference per second) on the deterministic append program in the interpretive mode, and also attains high performance in the nondeterministic program