Browse Prior Art Database

Improved Complement/Recomplement

IP.com Disclosure Number: IPCOM000120042D
Original Publication Date: 1991-Mar-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Aichelmann Jr, FJ: AUTHOR

Abstract

A method is proposed for eliminating the recomplement overhead which is not required for normal ECC operations.

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

Improved Complement/Recomplement

      A method is proposed for eliminating the recomplement
overhead which is not required for normal ECC operations.

      Convention complement/recomplement implementations result in
the addition of an inversion (i.e., Exclusive OR) being added to the
ECC facility.  This additional inverter adds to the ECC overhead
because it is always in the path. This proposal eliminates this
additional overhead by inverting the data during the correcting and
checking time before it is sent out.  The ECC facility produces the
same check bits for complemented data because the IBM codes are odd
weighted (i.e., produce an odd parity across the field covered by the
check bits).

      Fig. 1 shows the block diagram of a conventional recomplement
path in an ECC facility.  Fig. 2 depicts the enhanced recomplement
path resulting from implementing this proposed method.  This enhanced
recomplement path eliminates the overhead to produce recomplementing
of data.