A VLSI processor for fast track finding based on content addressable memories

We describe a VLSI processor for pattern recognition based on content addressable memory (CAM) architecture, optimized for on-line track finding in high-energy physics experiments. A large CAM bank stores all trajectories of interest and extracts the ones compatible with a given event. This task is naturally parallelized by a CAM architecture able to output identified trajectories, recognized among 2⁹⁶ possible combinations, in just a few 40 MHz clock cycles. We have developed this device (called the AMchip03 processor) for the silicon vertex trigger (SVT) upgrade at CDF using a standard-cell VLSI design methodology. This approach provides excellent pattern density, while sparing many of the complexities and risks associated to a full-custom design. On the other hand, the cost performance ratio is well more than one order of magnitude better than an FPGA-based design. This processor has a flexible and easily configurable structure that makes it suitable for applications in other experimental environments. We look forward to share this technology.