A programmable logic device includes an AND plane and an OR plane associated with the AND plane. At least one of the AND and OR planes includes an array of programmable memory elements which can be selectively programmed to define a desired logic function. In one form, a function cell designed for providing...http://www.google.com.hk/patents/US4992679?utm_source=gb-gplus-share專利 US4992679 - Programming logic device with multiple independent feedbacks per input/output terminal
