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. 28, 2000
Filed:
May. 05, 1998
Katsuya Nakashima, Nagasaki, JP;
Sony Corporation, Tokyo, JP;
Abstract
By providing a test circuit including a reference timing generator, a phase error detector, and a comparator, the output signal of the comparator is set in response to the timing of level change of the result of processing of the functional circuit. The phases of the reference pulse generated by the reference timing generator using a control signal as a trigger and the output signal of the comparator by the phase error detector are compared, and the level of a judging signal is set according to the result of the comparison. The judging signal is held temporally by a register, then output to an output pin through a buffer. Using a selector, the held signal of the register is output during the test operation, while the result of processing of the functional circuit is output during normal operation. As a result, it is possible to detect the quality of the chip without using an expensive LSI tester.