Functions classification approach to generate reconfigurable fine-grain logic based on Ambipolar Independent Double Gate FET (Am-IDGFET)

Abstract

Am-IDGFET is a new family of particular devices in view of the fact that it associates three benefits: (i) it is usually a 1-D electronic device (CNT or SiNW), meaning high mobility, achievable current density and high ION/IOFF ratio; (ii) Independently controlled gates which offers the device extra logic options; (iii) ambipolar behaviour opens the way for N- and P-type polarities in the same device via its back gate. The creativity of this work consists of looking at this new class of emerging technology as an opportunity for new design paradigms with no equivalent counterparts in CMOS technology. Nevertheless, to build a feasible and complete picture of ambipolar logic, innovative design approaches and tools are required. In this paper, we exploit functional classification, a powerful tool for the construction and analysis of Boolean functions, to build reconfigurable logic blocks by defining a hierarchical correlation between structures of functions classes with ambipolar devices. We demonstrate how this approach enables us to build Am-I DGFET-based n-input reconfigurable cells. Several dynamically reconfigurable 2-inputs logic cells with partial and full functionality are designed in this paper. We evaluate the performances of circuits designed from this approach in a case study focused on Double Gate Carbon Nanotube FET (DG-CNTFET) technology. Simulations results show efficiency to build fine grain reconfigurable cells with partial functionality. In the case of 9-functions reconfigurable cell, an improvement of 1.8X in terms of power delay product (PDP) is proved when compared to a CMOS-16nm technology. Fewer control signals are required and the area is reduced by 35% over CMOS technology.