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:
Apr. 22, 2003
Filed:
Nov. 08, 1999
Philip George Shephard, III, Round Rock, TX (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The present invention adds a programmable expect generator (PEG) that generates expected patterns of output for comparison to the actual outputs of an array while undergoing a complex test input sequence. The output of a programmable array built-in self test (PABIST) controller has its output increased to include separate control bits and a mask bit for a PEG. The PEG in one embodiment of the invention is substantially similar to a data control register that is programmed by a sequence of commands to generate the array input data patterns for testing an array. The program sequence that controls the PABIST and generates the input address, data and read/write patterns also outputs separate control bits to direct the PEG to generate expected outputs from the array when data from corresponding read addresses are read. The incorporation of a mask bit that accompanies each group of PEG control bits is used to inhibit the compare function that compares the output of the array to the output of the PEG. The mask bit controls when outputs of the array under test are compared to the PEG.