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:
Dec. 16, 1997
Filed:
May. 26, 1995
Christopher E Phillips, San Jose, CA (US);
Narendra Sankar, Sunnyvale, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A method and apparatus for fault testing a pipelined processor. In test mode, the stage registers are reconfigured as multiple input shift registers by switching in a few exclusive-OR gates. Also, the execute stage is prevented from executing any instructions. A unique sequential test sequence of instructions are run through the processor at normal speed. It is known that a particular test sequence (and thus a unique sequential input pattern to the MISR, assuming no faults) will result in a unique signature pattern existing in the MISR at the end of the sequence. If the signature pattern is not found in the MISR at the end of the test sequence, then it is known that a fault exists on the chip.