Construction of Soft-Error-Tolerant FF with Wide Error Pulse Detecting Capability

Shuangyu RUAN  Kazuteru NAMBA  Hideo ITO 

Publication
IEICE TRANSACTIONS on Information and Systems  Vol.E92-D  No.8  pp.1534-1541
Publication Date: 2009/08/01
Online ISSN: 1745-1361
Print ISSN: 0916-8532
Type of Manuscript: PAPER
Category: Dependable Computing
Keyword: 
soft error,  wide pulse,  flip-flop,  C-element,  delay element, 

Full Text: PDF(465.8KB)

Summary: 
In the recent high-density and low-power VLSIs, the occurrence of soft errors has become a significant problem. Recently, soft errors frequently occur on not only memory system but also logic circuits. Based on this standpoint, some constructions of soft-error-tolerant FFs were proposed. A conventional FF consists of some master and slave latches and C-elements. In the FF, soft error pulses occurring on combinational parts of logic circuits are corrected as long as the width of the pulses is narrow, that is within a specified width. However, error pulses with wide width are neither detected nor corrected in the FF. This paper presents a construction of soft-error-tolerant FFs by modifying the conventional soft-error-tolerant FF. The proposed FFs have the capability to detect error pulses having wide width as well as the capability to correct those having narrow width. The proposed FFs are also capable of detecting hard errors. The evaluation shows the soft-error-tolerant capability, AC characteristics, area overhead and power consumption of the FFs.