A logic block in a product-term based programmable device comprising a first logic gate, a second logic gate, a macrocell and a multiplexer. The first logic gate may be configured to generate a first output in response to a logical combination of a first number of product terms. The second logic gate...http://www.google.com.hk/patents/US6204685?utm_source=gb-gplus-share專利 US6204685 - Dual-function method and circuit for programmable device
