scholarly journals RADIX-10 PARALLEL DECIMAL MULTIPLIER

2012 ◽  
pp. 18-24
Author(s):  
MRUNALINI E. INGLE ◽  
TEJASWINI PANSE
Keyword(s):  
Tree Structure ◽  
Floating Point ◽  
Number Systems ◽  
Previous Design ◽  
New Generation ◽  
Carry Save Adders

This paper introduces novel architecture for Radix-10 decimal multiplier. The new generation of highperformance decimal floating-point units (DFUs) is demanding efficient implementations of parallel decimal multiplier. The parallel generation of partial products is performed using signed-digit radix-10 recoding of the multiplier and a simplified set of multiplicand multiples. The reduction of partial products is implemented in a tree structure based on a new algorithm decimal multioperand carry-save addition that uses a unconventional decimal-coded number systems. We further detail these techniques and it significantly improves the area and latency of the previous design, which include: optimized digit recoders, decimal carry-save adders (CSA’s) combining different decimal-coded operands, and carry free adders implemented by special designed bit counters.

scholarly journals A Vector-Like Reconfigurable Floating-Point Unit for the Logarithm

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Nikolaos Alachiotis ◽  
Alexandros Stamatakis
Keyword(s):  
Reconfigurable Computing ◽  
Lookup Table ◽  
Floating Point ◽  
Double Precision ◽  
Single Precision ◽  
Reconfigurable Devices ◽  
Floating Point Unit ◽  
New Generation ◽  
Logarithm Function

The use of reconfigurable computing for accelerating floating-point intensive codes is becoming common due to the availability of DSPs in new-generation FPGAs. We present the design of an efficient, pipelined floating-point datapath for calculating the logarithm function on reconfigurable devices. We integrate the datapath into a stand-alone LUT-based (Lookup Table) component, the LAU (Logarithm Approximation Unit). We extended the LAU, by integrating two architecturally independent, LAU-based datapaths into a larger component, the VLAU (vector-like LAU). The VLAU produces 2 results/cycle, while occupying the same amount of memory as the LAU. Under single precision, one LAU is 12 and 1.7 times faster than the GNU and Intel Math Kernel Library (MKL) implementations, respectively. The LAU is also 1.6 times faster than the FloPoCo reconfigurable logarithm architecture. Under double precision, one LAU is 20 and 2.6 times faster than the respective GNU and MKL functions and 1.4 times faster than the FloPoCo logarithm. The VLAU is approximately twice as fast as the LAU, both under single and double precision.

scholarly journals Structure–property–activity relationships in a pyridine containing azine-linked covalent organic framework for photocatalytic hydrogen evolution

2017 ◽  
Vol 201 ◽  
pp. 247-264 ◽  
Author(s):  
Frederik Haase ◽  
Tanmay Banerjee ◽  
Gökcen Savasci ◽  
Christian Ochsenfeld ◽  
Bettina V. Lotsch
Keyword(s):  
Hydrogen Evolution ◽  
Rational Design ◽  
Molecular Level ◽  
Optoelectronic Properties ◽  
Atomic Scale ◽  
Structure Property ◽  
Photocatalytic Hydrogen Evolution ◽  
Previous Design ◽  
Nitrogen Substitution ◽  
New Generation

Organic solids such as covalent organic frameworks (COFs), porous polymers and carbon nitrides have garnered attention as a new generation of photocatalysts that offer tunability of their optoelectronic properties both at the molecular level and at the nanoscale. Owing to their inherent porosity and well-ordered nanoscale architectures, COFs are an especially attractive platform for the rational design of new photocatalysts for light-induced hydrogen evolution. In this report, our previous design strategy of altering the nitrogen content in an azine-linked COF platform to tune photocatalytic hydrogen evolution is extended to a pyridine-based photocatalytically active framework, where nitrogen substitution in the peripheral aryl rings reverses the polarity compared to the previously studied materials. We demonstrate how simple changes at the molecular level translate into significant differences in atomic-scale structure, nanoscale morphology and optoelectronic properties, which greatly affect the photocatalytic hydrogen evolution efficiency. In an effort to understand the complex interplay of such factors, we carve out the conformational flexibility of the PTP-COF precursor and the vertical radical anion stabilization energy as important descriptors to understand the performance of the COF photocatalysts.

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