Low-Cost Stochastic Number Generators for Stochastic Computing

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


Stochastic unary computing provides low-area circuits. However, the required area consuming stochastic number generators (SNGs) in these circuits can diminish their overall gain in area, particularly if several SNGs are required. We propose area-efficient SNGs by sharing the permuted output of one linear feedback shift register (LFSR) among several SNGs. With no hardware overhead, the proposed architecture generates stochastic bit streams with minimum stochastic computing correlation (SCC). Compared to the circular shifting approach presented in prior work, our approach produces stochastic bit streams with 67% less average SCC when a 10-bit LFSR is shared between two SNGs. To generalize our approach, we propose an algorithm to find a set of m permutations ( n > m > 2 ) with a minimum pairwise SCC, for an n -bit LFSR. The search space for finding permutations with an exact minimum SCC grows rapidly when n increases and it is intractable to perform a search algorithm using accurately calculated pairwise SCC values, for n > 9. We propose a similarity function that can be used in the proposed search algorithm to quickly find a set of permutations with SCC values close to the minimum one. We evaluate our approach for several applications. The results show that, compared to prior work, it achieves lower mean-squared error (MSE) with the same (or even lower) area. Additionally, based on simulation results, we show that replacing the comparator component of an SNG circuit with a weighted binary generator can reduce SCC.

Original languageEnglish
Article number8966562
Pages (from-to)992-1001
Number of pages10
JournalIEEE Transactions on Very Large Scale Integration (VLSI) Systems
Issue number4
StatePublished - Apr 2020

Bibliographical note

Publisher Copyright:
© 1993-2012 IEEE.


  • Linear feedback shift register (LFSR)
  • permutation
  • stochastic computing (SC)
  • stochastic number generator (SNG)

ASJC Scopus subject areas

  • Software
  • Hardware and Architecture
  • Electrical and Electronic Engineering


Dive into the research topics of 'Low-Cost Stochastic Number Generators for Stochastic Computing'. Together they form a unique fingerprint.

Cite this