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:
Sep. 03, 1991
Filed:
Feb. 02, 1990
Applicant:
Inventors:
Richard G Cliff, Devon, GB;
Neil S Hastie, Devon, GB;
Assignee:
Plessey Overseas Limited, Ilford, GB;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11C / ; G11C / ;
U.S. Cl.
CPC ...
365201 ; 371 211 ; 371 212 ;
Abstract
A circuit arrangement comprising, for each bit location in a column of a RAM, an input shift register, a multiplexer and a comparator. The input data bit is stored in the shift register, and the multiplexer is arranged during a write cycle, to write the data bit into a bit position. During a verification cycle, the multiplexer is arranged to write the inverse data bit into the same position, and the comparator compares the output bit position of the RAM with the inverse data bit. The result is stored in the shift register, which can be down-loaded for analysis.