The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 05, 1986
Filed:
Nov. 07, 1983
John C Manton, Marlboro, MA (US);
William F Bruckert, Hudson, MA (US);
Alfred J Dellicicchi, Acton, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
In a data processing system, a memory (32) consists of data words and associated error-correction codes that are independently accessible; it is possible simultaneously to read a data word and write its associated error-correction code. This allows a memory-control circuit (30) immediately to store in the memory (32) a data word sent by a processor (10) while it is concurrently in the process of generating the error-correction code for that data word. The result is that the memory-control circuit (30) can subsequently fetch the newly stored data word before storage of its associated error-correction code is complete. This reduces delays involved in error-correction-code generation. The data word includes not only non-redundant information but also parity bits that both the processor (10) and the memory-control circuit (30) employ to determine whether a data word is correct. If the memory-control circuitry (30) determines that a word that it has forwarded to the processor (10) is incorrect, it immediately fetches the corresponding error-correction code and corrects the location in memory. Then, when the processor (10) finds that the parity is incorrect in the data word, it repeats its request for the data word in question, which the memory-control circuit (30) has corrected in the memory (32).