ECC-Aware Fast and Reliable Pattern Matching Redundancy Analysis for Highly Reliable Memory

Donghyun Han,Seungtaek Lee,Hayoung Lee,Sungho Kang

doi:10.1109/access.2021.3115496

Abstract

Advanced capacity and density of memory have resulted in an increase in the probability of memory faults. The in-memory Error Correction Code (ECC), which solves this problem, is a widely used technology to improve the yield of highly integrated memory. However, the use of in-memory ECC causes problems that have not been considered in memory repair algorithms. Redundancy analysis is effective for repairing memory with redundant memory and in-memory ECC. In this paper, an ECC-aware fast and reliable pattern matching redundancy analysis algorithm for memory using both spare memory and in-memory ECC is proposed. This algorithm simplifies large-scale fault groups using in-memory ECC and includes an early termination method that can determine whether a memory that cannot be repaired with line spares can be repaired considering in-memory ECC. Experimental results show that the proposed pattern matching redundancy analysis algorithm achieves a similar yield but 14.6% less RA time and 8.6 times higher reliability compared to the existing redundancy analysis algorithms.

Highlights

Advances in memory production and design technology have led to steady improvements in memory cell density, performance, power consumption efficiency, and cost
The in-memory Error Correction Code (ECC) is a technology proposed to correct soft errors occurring during operation; its use for improving yield is a major goal [13], [16], [19], [20], [22], [23]
A single fault in a codeword is corrected by ECC to skip the faults located in a large group and convert it to a group capable of pattern matching, or to fix a memory that cannot be repaired with only line spares

Summary

INTRODUCTION

Advances in memory production and design technology have led to steady improvements in memory cell density, performance, power consumption efficiency, and cost. The final solution is determined by combining the row and column line spares required to repair each group of faults; it does not achieve high repair rates For this reason, Very Efficient RA (VERA) [7] has been proposed where the use of the fault group method is the same, but it is possible to repair all faulty memories. According to the line-based replacement policy, one line spare must be used to repair a single fault, whereas an in-memory ECC can repair any number of single faults Because of these features, the in-memory ECC is a technology proposed to correct soft errors occurring during operation; its use for improving yield is a major goal [13], [16], [19], [20], [22], [23]. A new early termination algorithm is proposed to quickly determine whether repair is possible, by considering in-memory ECC for memory that cannot be repaired with line spares

REPAIR RATE

RELIABILITY ISSUES USING ECC WITH RA

PERFORMANCE ANALYSIS OF THE PROPOSED RA

Findings

CONCLUSION