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:
Nov. 10, 1992
Filed:
Aug. 20, 1991
Mishio Hayashi, Saitama, JP;
Advantest Corporation, Tokyo, JP;
Abstract
An input pattern is re-timed in a re-timing circuit by an input clock signal of the same frequency as that of the input pattern, and the re-timed input pattern and a reference pattern generated by a reference pattern generator in synchronization with the input clock signal are compared by a digital error detector to detect a mismatch between them. When the error rate dependent on the thus detected mismatch is larger than a predetermined value, an inhibit control circuit inhibits one input clock pulse which is applied to the reference pattern generator, and when the error rate is smaller than the predetermined value, the inhibit control circuit generates a pattern synchronization establishment signal. When the pattern synchronization establishment signal disappears, a one-shot circuit generates a pulse of a certain width, and if the pattern synchronization establishment signal is not generated again in this while, a T flip-flop is triggered by the trailing edge of the pulse of the certain width. The output of the T flip-flop thus triggered is applied to an inverter, which inverts the polarity of the input pulse which is applied to the reference pattern generator and the re-timing circuit.