Two operand binary adders with Threshold Logic

Citation
Jf. Ramos et Ag. Bohorquez, Two operand binary adders with Threshold Logic, IEEE COMPUT, 48(12), 1999, pp. 1324-1337
Citations number
13
Categorie Soggetti
Computer Science & Engineering
Journal title
IEEE TRANSACTIONS ON COMPUTERS
ISSN journal
00189340 → ACNP
Volume
48
Issue
12
Year of publication
1999
Pages
1324 - 1337
Database
ISI
SICI code
0018-9340(199912)48:12<1324:TOBAWT>2.0.ZU;2-S
Abstract
The central topic of this paper is the implementation of binary adders with Threshold Logic using a new methodology that introduces two innovations: t he use of the input and output carries of each bit for obtaining all the su m bits and a modification of the classic Carry Lookahead adder technique th at allows us to obtain the expressions of the generation and propagation ca rries in a more appropriate way for Threshold Logic. In this way, it has be en possible to systematize the process of design of a binary adder with Thr eshold Logic relating all its important parameters: number of bits of the o perands, depth, size, maximum fan-in, and maximum weight. The results obtai ned are an improvement on those published to date and are summarized as fol lows: Depth 2 adder: s = 2n, omega(max) = 2(n), f(max) = 2n + 1. Depth 3 ad der: s = 4n - 2[n/\root n\], omega(max) = 2([n/\root n\]), f(max) = 2[n/\ro ot n\] + 1. Depth d adder (asymptotic behavior): s = O(n), omega(max) = O(2 (root n)), f(max) = O((e-1)root n). If the weights are bounded by omega(max ):n(max) = O(log(d-1) u(max)), d(min) = O(log n/log(log omega(max))).