Leading Zero Detector Research Articles

T-Count Optimized Quantum Circuit Designs for Single-Precision Floating-Point Division

The implementation of quantum computing processors for scientific applications includes quantum floating points circuits for arithmetic operations. This work adopts the standard division algorithms for floating-point numbers with restoring, non-restoring, and Goldschmidt division algorithms for single-precision inputs. The design proposals are carried out while using the quantum Clifford+T gates set, and resource estimates in terms of numbers of qubits, T-count, and T-depth are provided for the proposed circuits. By improving the leading zero detector (LZD) unit structure, the proposed division circuits show a significant reduction in the T-count when compared to the existing works on floating-point division.

Design of a reversible single precision floating point subtractor

In recent years, Reversible logic has emerged as a major area of research due to its ability to reduce the power dissipation which is the main requirement in the low power digital circuit design. It has wide applications like low power CMOS design, Nano-technology, Digital signal processing, Communication, DNA computing and Optical computing. Floating-point operations are needed very frequently in nearly all computing disciplines, and studies have shown floating-point addition/subtraction to be the most used floating-point operation. However, few designs exist on efficient reversible BCD subtractors but no work on reversible floating point subtractor. In this paper, it is proposed to present an efficient reversible single precision floating-point subtractor. The proposed design requires reversible designs of an 8-bit and a 24-bit comparator unit, an 8-bit and a 24-bit subtractor, and a normalization unit. For normalization, a 24-bit Reversible Leading Zero Detector and a 24-bit reversible shift register is implemented to shift the mantissas. To realize a reversible 1-bit comparator, in this paper, two new 3x3 reversible gates are proposed The proposed reversible 1-bit comparator is better and optimized in terms of the number of reversible gates used, the number of transistor count and the number of garbage outputs. The proposed work is analysed in terms of number of reversible gates, garbage outputs, constant inputs and quantum costs. Using these modules, an efficient design of a reversible single precision floating point subtractor is proposed. Proposed circuits have been simulated using Modelsim and synthesized using Xilinx Virtex5vlx30tff665-3. The total on-chip power consumed by the proposed 32-bit reversible floating point subtractor is 0.410 W.

Implementation of a H.264/AVC SVC decoder with multi-symbol prediction CAVLC for advanced T-DMB receiver

This paper presents a low-cost high-performance H.264/AVC SVC decoder with multi-symbol prediction context-based adaptive variable length coding (CAVLC) for advanced T-DMB receiver. Proposed multi-symbol prediction CAVLC mainly consists of a simple arithmetic operation unit with reduced look-up tables and a leading zero detector. We also propose a multi-symbol run_before decoder and it decodes more than 2.5 symbols in a cycle. Gate count of a H.264/AVC SVC decoder is about 1,300K gates when synthesized with 0.18 um CMOS process and it can be operated at 120 MHz clock frequency. For the verification of a H.264/AVC SVC decoder chip, prototype mobile movie player systems have been implemented using a 7 inch LCD and USB controller.

An algorithmic and novel design of a leading zero detector circuit: comparison with logic synthesis

A novel way of implementing the leading zero detector (LZD) circuit is presented. The implementation is based on an algorithmic approach resulting in a modular and scalable circuit for any number of bits. We designed a 32 and 64 bit leading zero detector circuit in CMOS and ECL technology. The CMOS version was designed using both: logic synthesis and an algorithmic approach. The algorithmic implementation is compared with the results obtained using modern logic synthesis tools in the same 0.6 /spl mu/m CMOS technology. The implementation based on an algorithmic approach showed an advantage compared to the results produced by the logic synthesis. ECL implementation of the 64 bit LZD circuit was simulated to perform in under 200 ps for nominal speed. >

Algorithmic design of a hierarchical and modulator leading zero detector circuit

A novel way of implementing the leading zero detector (LZD) circuit is described. The implementation is based on an algorithmic approach resulting in a modular and scalable circuit for any number of bits. This approach to LZD design yields both speed and area advantages over logic synthesis.