In general, existing logic synthesis methods for majority logic are limited to 3-input gates (maj-3). However, since majority gates with larger fan-in have been proposed for different emerging nanotechnologies, it has become important to consider such gates in the synthesis process. This paper proposes a novel majority logic synthesis flow where the gates can have an arbitrary number of inputs. The proposed approach is based on the relationship between majority and threshold logic functions. The proposed methods obtain an average reduction of 10% on the number of nodes when compared to a previous work that uses both maj-3 and maj-5 gates. When compared to the previous maj-3 synthesis, the average reduction on number of nodes is 14%.

This paper presents two main contributions toward efficient very large scale integration circuits mapped with simple cells: 1) a complete synthesis flow to provide good-quality circuits mapped only with simple cells; and 2) an area-oriented, level-aware buffering algorithm based on inverter trees to fix cell fanout violations. An effective pattern-based algorithm to identify XORs/XNORs on and-inverter graphs is also presented. We show that efficient implementations in terms of inverter count, transistor count, area, power, and delay can be generated from circuits with a reduced number of both simple cells and inverters, combined with XOR/XNOR-based optimizations. The proposed buffering algorithm can handle all unfeasible fanout occurrences, while: 1) optimizing the number of added inverters and 2) assigning cells to the inverter tree based on their level criticality. When comparing with academic and commercial approaches, we are able to simultaneously reduce the average number of inverters, transistors, area, power dissipation, and delay up to 48%, 4%, 8%, 14%, and 16%, respectively.

This paper presents a novel and effective logic synthesis flow able to identify threshold logic functions during the technology mapping process. It provides more efficient logic covering, exploring also redundant cuts. Moreover, the proposed design flow takes into account different circuit area estimations, such as the sum of input weights and threshold values, the gate fanin and the number of threshold logic gates. As a result, the mapped circuits present a reduction up to 47% and 67% in area and logic depth, respectively, in comparison to the most recent related approaches.

This paper presents two main contributions toward efficient VLSI circuits mapped with simple cells: (1) a complete synthesis flow to provide good-quality circuits mapped only with simple cells; and (2) an area-oriented, level-aware buffering algorithm based on inverter trees to fix cell fanout violations. We show that efficient implementations in terms of inverter count, transistor count, area, power and delay can be generated from circuits with a reduced number of both simple cells and inverters, combined with XOR/XNOR-based optimizations. The proposed buffering algorithm can handle all unfeasible fanout occurrences, while (i) optimizing the number of added inverters; and (ii) assigning cells to the inverter tree based on their level criticality. When comparing with academic and commercial approaches, we are able to simultaneously reduce the average number of inverters, transistors, area, power dissipation and delay up to 48%, 4%, 8%, 14%, and 16%, respectively.

This paper presents a novel approach to synthesize circuits based on threshold logic gates (TLGs). Emerging technologies, such as memristors, spintronics devices and tunneling diodes, are able to build this class of gates efficiently. For this reason, threshold logic is a promising alternative to conventional CMOS logic. The proposed approach is based on pruning non-threshold-logic cuts in order to limit the search space during technology mapping. As a result, both the number of TLGs and logic depth of the synthesized circuits are reduced. Experimental results have shown that, compared to the state-of-the-art methods, the TLG count is reduced by 8% and logic depth is reduced by 46%.

This paper presents the 15nm FinFET-based Open Cell Library (OCL) and describes the challenges in the methodology while designing a standard cell library for such advanced technology node. The 15nm OCL is based on a generic predictive state-of-the-art technology node. The proposed cell library is intended to provide access to advanced technology node for universities and other research institutions, in order to design digital integrated circuits and also to develop cell-based design flows, EDA tools and associated algorithms. Developing a 15nm standard cell library brings out design challenges which are not present in previous technology nodes. Some of these challenges include double-patterning for both metal and poly layers, a very restrictive set of physical design rules, and the demand for lithography-friendly patterns. This paper discusses the development of the library considering the challenges associated with advanced technology nodes.

This paper presents an improved benchmark suite to jointly consider logic synthesis and physical design. Usually, benchmark circuits were provided by the physical design and the logic synthesis communities separately, according to their specific needs. The files provided for each benchmark set were restricted to the views necessary for the community. Additional specifications of design intents are necessary to express optimization goals that can be shared by logic synthesis and physical design communities, as circuits alone do not carry sufficient information to establish a benchmark with a clear optimization goal. In this paper, we describe benchmarks as a set composed of circuits, design intents (constraints), floorplan, target library and technology. Disregarding pieces of information provided for the benchmarks can change the associated criticality and affect the combined or isolated outcome of logic synthesis and physical design. The proposition of this benchmark suite brings attention to the problem of considering adequately the complete context of design intent throughout the flow.