Patent ID: 7911229
Filing Date: 2011-03-22
Classification: H03K

Abstract:
1. A programmable logic device (PLD) having a configurable interconnect structure including longline buses each having a plurality of longlines that each extends through a plurality of substantially repeating tile structures of the PLD, where the configurable interconnect structure is characterized by: (a) each of the longlines having plural tristate drivers connected thereto and operable to drive that longline; (b) each of the longline-driving tristate drivers having an input terminal, an output enabling terminal and an output terminal that is connected to the corresponding longline of that tristate driver; (c) each of the longline-driving tristate drivers having a corresponding input signal selecting multiplexer coupled to the input terminal of that tristate driver, the input signal selecting multiplexer being operable to supply a selected one of one or more input signals received by the input signal selecting multiplexer, if any are received, to the corresponding input terminal of the tristate driver; (d) each input signal selecting multiplexer being responsive to a respective input selecting signal that is conveyable to that input signal selecting multiplexer, where the input selecting signal can represent 2 (e) each input signal selecting multiplexer of a respective tristate driver having a plurality of, but no more than 2 (f) each input signal selecting multiplexer being structured such that a predetermined one of the 2 (g) the output enabling terminal of each longline-driving tristate driver is controlled by a respective output enabling circuit that is responsive to the respective input selecting signal of the corresponding input signal selecting multiplexer of that tristate driver, where the respective output enabling circuit is structured to prevent the corresponding tristate driver from being in a signal outputting state other than a high impedance (Hi-Z) output state when respective input selecting signal represents said no-usable-input-selected state.