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. 13, 2001
Filed:
Aug. 31, 2000
Takeshi Onodera, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A semiconductor circuit for compressing or encoding output data of a scan path circuit, able to realize a circuit test and fault analysis by the scan path circuit, and capable of preventing the configuration of a combinational circuit from being guessed from the input and output. Predetermined mode key data is input by being mixed in input data to a scan path circuit during a scan mode operation so as to be fetched by a mode key circuit embedded in the scan path circuit. The mode key data is fetched by the mode holding circuit from the mode key circuit and a mode signal BE is generated in accordance with the mode key data during a system mode operation. When the mode key data has a predetermined pattern, the mode key signal becomes a predetermined set value, and an output signal of the scan path circuit is output as it is in accordance therewith. Otherwise, since the output signal of the scan path circuit is encoded and output, the output of the scan path circuit can be concealed in accordance with need.