Automatic FPGA Placement Configuration for Customer Designs

Searching for new ways to improve the efficiency of integrated circuits (IC) led to the development of specialized heterogeneous configurable IC (FPGA) and systems-on-a-chip. Their key feature is an extended interpretation of standard cell library, containing ready-to-use IP cores along with standard cells. Specific customer designs require the flexibility of the configurable heterogeneous IC’s architecture and, therefore, automatic CAD clustering and placement algorithms configuration. The development of efficient configuration methods and algorithms is impossible without relying on the mathematical apparatus. In this work, such mathematical apparatus is provided. The authors described a set-theoretic model of a hierarchical project and formalized the hierarchical approach to the netlist, using the apparatus of mathematical logic, set and graph theories. The correspondence between the customers designs’ elements and FPGA’s elements has been formalized to provide fast clustering and placement configuration. The obtained results provide the basis for future efficient methods for automatic placement and clustering configuration.

Low-Latency Bit-Accurate Architecture for Configurable Precision Floating-Point Division

Floating-point division is indispensable and becoming increasingly important in many modern applications. To improve speed performance of floating-point division in actual microprocessors, this paper proposes a low-latency architecture with a multi-precision architecture for floating-point division which will meet the IEEE-754 standard. There are three parts in the floating-point division design: pre-configuration, mantissa division, and quotient normalization. In the part of mantissa division, based on the fast division algorithm, a Predict–Correct algorithm is employed which brings about more partial quotient bits per cycle without consuming too much circuit area. Detailed analysis is presented to support the guaranteed accuracy per cycle with no restriction to specific parameters. In the synthesis using TSMC, 90 nm standard cell library, the results show that the proposed architecture has ≈63.6% latency, ≈30.23% total time (latency × period), ≈31.8% total energy (power × latency × period), and ≈44.6% efficient average energy (power × latency × period/efficient length) overhead over the latest floating-point division structure. In terms of latency, the proposed division architecture is much faster than several classic processors.

Approximate Full Adders for Energy Efficient Image Processing Applications

This paper proposes six novel approximate 1-bit full adders (AFAs) for inexact computing. The six novel AFAs namely AFA1, AFA2, AFA3, AFA4, AFA5, and AFA6 are derived from state-of-the-art exact 1-bit full adder (EFA) architectures. The performance of these AFAs is compared with reported AFAs (RAAs) in terms of design metrics (DMs) and peak-signal-to-noise-ratio (PSNR). The DMs under consideration are power, delay, power-delay-product (PDP), energy-delay-product (EDP), and area. For a fair comparison, the EFAs and proposed AFAs along with RAAs are described in Verilog, simulated, and synthesized using Cadences’ RC tool, using generic 180 nm standard cell library. The unconstrained synthesis results show that: among all the proposed AFAs, the AFA1 and AFA2 are found to be energy-efficient adders with high PSNR. The AFA1 has a total [Formula: see text][Formula: see text][Formula: see text]W, [Formula: see text][Formula: see text]ps, [Formula: see text][Formula: see text]fJ, [Formula: see text][Formula: see text]Js, [Formula: see text][Formula: see text][Formula: see text]m2, and [Formula: see text][Formula: see text]dB. And the AFA2 has the total [Formula: see text][Formula: see text][Formula: see text]W, [Formula: see text][Formula: see text]ps, [Formula: see text][Formula: see text]fJ, [Formula: see text][Formula: see text]Js, [Formula: see text][Formula: see text][Formula: see text]m2, and [Formula: see text][Formula: see text]dB.