Each output signal of programmable logic circuitry is made programmably available to drive one or more of a plurality of tri-statable input/output pins of the circuitry. Each output signal is also made programmably available to provide the output enable signal for one or more of a multiplicity of those...http://www.google.es/patents/US5936425?utm_source=gb-gplus-sharePatente US5936425 - Tri-statable input/output circuitry for programmable logic
Tri-statable input/output circuitry for programmable logic
