Clocking-Based Coplanar Wire Crossing Scheme for QCA

A tiled programmable fabric using QCA

“…[9]. This Time-Division Multiplexing based wire crossing scheme eliminates the need for two types of cells and proves to be robust and reliable compared to the traditional coplanar crossings.…”

“…While the need to incorporate these special structures have forced a few architectures [9] to go for NAND-gates and large basic blocks, their frailness have affected the overall robustness of other architectures. It is rather intuitive that an alternative coplanar wire crossing method can open up new avenues in programmable QCA device design.…”

“…It is rather intuitive that an alternative coplanar wire crossing method can open up new avenues in programmable QCA device design. Hence we base our p-QCA architecture on the new coplanar wire crossing method proposed by us, which depends only on clocking and not on the orientations of the cells [9]. This method is briefly described in Section III.…”

“…This channel, an interesting application of our Clocking-based Coplanar Cross-over scheme, is designed to carry both its input signals simultaneously [9]. The individual signals can be tapped out of the channel any number of times by employing the same clocking pattern used in Fig.…”

“…The proposed p-QCA can be programmed to implement a given design by selectively activating the required tiles. By 'activating', we mean driving the tile with one of the signals in the clocking scheme -one of the seven signals of the 8-phase scheme proposed by us in this case [9]. When 'deactivated', the tile is driven by the NULL signal -a constant field, which forces the cells to be in the RELAX phase.…”