Patent US4733392A successfully refreshed from Google Patents.
US4733392A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fail memory equipment in memory tester
Assignee: Hitachi Ltd
•
Filing: 1985-04-03
•
Granted: 1988-03-22
•
Expires: 2005-04-03
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 17:50
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)
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 |