Signal routing resource tiles that can be manipulated as circuit "cells" in that they can be readily characterized and implemented on a programmable logic device, e.g., a field programmable gate array (FPGA). In one embodiment, vertical placement and horizontal placement routing resource tiles are provided....http://www.google.com.hk/patents/US5880598?utm_source=gb-gplus-share專利 US5880598 - Tile-based modular routing resources for high density programmable logic device
