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US4733392A Expired / Lapsed US ⏱️ 0.0 years remaining

Fail memory equipment in memory tester

Assignee: Hitachi Ltd
•
Filing: 1985-04-03
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Granted: 1988-03-22
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Expires: 2005-04-03
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Abstract

Abstract A fail memory equipment has a plurality of memory blocks which can be changed in their combinations serially or in parallel in accordance with the capacity of a memory to be tested, the number of channels to be tested simultaneously and the testing speed. The single fail memory equipment operates in an interleave fetching mode for a high speed test, in a parallel fetching mode for a multi-channel test or in a serial fetching mode for testing a memory of a large capacity, thereby realizing a high speed test, a large capacity memory test and a simultaneous multi-channel test.

Inventors

  • 👤 Kazuo Yamaguchi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 16:10
CPC Classifications
G; G11; G11C; G11C29/00; G11C29/56; G01; G01R; G01R31/00; G01R31/28; G01R31/317; G01R31/3181; G01R31/319; G01R31/3193; G01R31/31935

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 284 words
A fail memory equipment comprising: memory means having an equal number of memory blocks and input channels through which results of a memory test are inputted to said memory equipment; address input means temporarily storing addresses of memory test, for subsequently supplying an address to a corresponding memory block and selecting a memory cell of the corresponding memory block by decoding the address in response to a decode signal; test result input means selecting an input channel carrying the memory test result in response to a mode designation and temporarily storing the memory test result, for subsequently writing the memory test result into a corresponding memory block; serial/parallel control means responsive to the mode designation to produce the deocde signal from an address signal sent from said address input means; and clock control means responsive to a test clock and the mode designation to produce a storage instruction clock for the temporary storage of the address of memory test and the memory test result and a write clock for writing the memory test result into the memory block in accordance with an interleave mode, a serial mode or a parallel mode, whereby the memory test results obtained at a high speed from a memory being tested through input channels are written in parallel into the respective memory blocks under the interleave mode the memory test result obtained at a low speed from a large capacity memory being tested through an input channel are serially written into the respective memory blocks under the serial mode, and the memory test result obtained from a number of memories being tested simultaneously through input channels are written in parallel into the respective memory blocks under the parallel mode.
Claim 2
Dependent Claim 284 words
A fail memory equipment comprising: memory means having an equal number of memory blocks and input channels through which results of a memory test are inputted to said memory equipment; address input means temporarily storing addresses of memory test, for subsequently supplying an address to a corresponding memory block and selecting a memory cell of the corresponding memory block by decoding the address in response to a decode signal; test result input means selecting an input channel carrying the memory test result in response to a mode designation and temporarily storing the memory test result, for subsequently writing the memory test result into a corresponding memory block; serial/parallel control means responsive to the mode designation to produce the deocde signal from an address signal sent from said address input means; and clock control means responsive to a test clock and the mode designation to produce a storage instruction clock for the temporary storage of the address of memory test and the memory test result and a write clock for writing the memory test result into the memory block in accordance with an interleave mode, a serial mode or a parallel mode, whereby the memory test results obtained at a high speed from a memory being tested through input channels are written in parallel into the respective memory blocks under the interleave mode the memory test result obtained at a low speed from a large capacity memory being tested through an input channel are serially written into the respective memory blocks under the serial mode, and the memory test result obtained from a number of memories being tested simultaneously through input channels are written in parallel into the respective memory blocks under the parallel mode.

References Cited (Backward Citations)

US4369511A Cited
US4414665A Cited
US4541090A Cited
US4628509A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-03-22 1991-09-21 1992-03-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-03-22 1995-09-21 1996-03-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-03-22 1999-09-21 2000-03-22 $7700.00 Window Closed / Lapsed

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