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.:

US 7197679 B1

PDF
Full Text
Expired
Date of Patent:
Mar. 27, 2007

Filed:

Apr. 01, 2005
Applicants:

Dirk Fuhrmann, Essex Junction, VT (US);

Reidar Lindstedt, München, DE;

Inventors:

Dirk Fuhrmann, Essex Junction, VT (US);

Reidar Lindstedt, München, DE;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11C 29/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

An integrated semiconductor memory operates in synchronization with a clock signal in a normal operating state and is switched from the normal operating state to a test operating state by applying a combination of control signals. During a first test cycle, selection transistors for memory cells are turned on by asynchronously actuating the semiconductor memory using a state change in a control signal. In a second test cycle, the memory content of at least one of the previously activated memory cells is read by synchronously actuating the semiconductor memory using a second signal combination of control signals. By shifting the timing of a signal edge which prompts the state change in the first test cycle close to the time at which the second signal combination is applied in the second test cycle, it is possible to test short reading times which are within one period of the clock signal.


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