Title:
TESTER AND SELECTOR
Document Type and Number:
WIPO Patent Application WO/2007/086214
Kind Code:
A1
Abstract:
A tester for testing a memory under test having blocks and a repair column. The tester comprises a test unit, a flag memory storing a flag indicating whether each column is good or defective, a count memory for storing number of blocks defective in each column, a fail write section for writing a flag indicating a defective in a flag memory if the test result shows a defective and if the flag in the flag memory about the corresponding column shows a defective, a count section for incrementing the number of blocks of the count memory about the corresponding column if the test result shows a defective and if a flag indicating a defective is not stored about the corresponding column, and a selecting section for selecting a column to be replaced with a repair column according to the number of blocks defective in each column.
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Inventors:
DOI MASARU (JP)
Application Number:
PCT/JP2006/325418
Publication Date:
August 02, 2007
Filing Date:
December 20, 2006
Export Citation:
Assignee:
ADVANTEST CORP (JP)
DOI MASARU (JP)
DOI MASARU (JP)
International Classes:
G11C29/44; G01R31/28; G11C16/02; G11C16/06
Foreign References:
| JP2002117699A | 2002-04-19 | |||
| JP2001006388A | 2001-01-12 | |||
| JP2001319493A | 2001-11-16 |
Attorney, Agent or Firm:
RYUKA, Akihiro (22-1 Nishi-Shinjuku 6-chom, Shinjuku-ku Tokyo 05, JP)
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