Browse Prior Art Database

Correction of Subgroups Within an ECC Word

IP.com Disclosure Number: IPCOM000101704D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Aichelmann, FJ, Jr: AUTHOR

Abstract

A method is proposed for providing a way to correct subgroups within an ECC word. Additionally, this development makes it possible to extend parity/check bit ECC coding for applications that do not require processing the full ECC word.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Correction of Subgroups Within an ECC Word

       A method is proposed for providing a way to correct
subgroups within an ECC word.  Additionally, this development makes
it possible to extend parity/check bit ECC coding for applications
that do not require processing the full ECC word.

      With conventional memory ECC implementations, the ECC
facilities normally process the entire ECC word at the same time.
Read-only memories (ROM) are structured with narrow words which are
combined into an ECC configuration at a wider word for minimizing the
effects of ECC overhead.  This proposal groups individual bits into
multiple user words which can be processed by a combination of parity
and check bits.  The parity bit is a special check bit associated
with each user word.

      Fig. 1 describes the basic "H" matrix consisting of parity and
check bits grouped into 4 user words (1 through 4).  The individual
data bits are designated A, B, C, and D for each of the user words.
A parity bit (P1, P2, P3, P4) is associated with each of the user
words along with check bits (C1, C2, C3, C4).  This organizational
grouping enables the processing of the ECC on a subgroup basis rather
than a full ECC word.  As a result, this technique provides a way to
require less circuits, reduced chip area, and lower power to process
a user word.  Fig. 2 depicts the logical embodiment of ECC correction
of subgroup of the "H" matrix of Fig. 1.