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:
May. 10, 2011
Filed:
Oct. 12, 2006
Tom Waayers, Sint Michielsgestel, NL;
Tom Waayers, Sint Michielsgestel, NL;
NXP B.V., Eindhoven, NL;
Abstract
A shift register circuit is provided for storing instruction data for the testing of an integrated circuit core. The shift register circuit comprises a plurality of stages, each stage comprising a serial input (si) and a serial output (so) and a parallel output (wir_output) comprising one terminal of a parallel output of the shift register circuit. A first shift register storage element () is for storing a signal received from the serial input (si) and providing it to the serial output (so) in a scan chain mode of operation. A second parallel register storage element () is for storing a signal from the first shift register storage element () and providing it to the parallel output (wir_output) in an update mode of operation. The stage further comprises a feedback path () for providing an inverted version of the parallel output (wir_output) to the first shift register storage element () in a test mode of operation. This configuration enables testing of each shift register stage using the existing control lines. In particular, the inverted signal can be clocked to propagate through the shift register storage element and the parallel register storage element, and the eventual inversion of the output is monitored to indicate that the inverted signal has propagated through the circuitry.