Redundancy analyzer for automatic memory tester
First Claim
1. Memory test apparatus for testing a memory under test (MUT) formed from physical structures which define a plurality of storage locations organized into a plurality of regions, said apparatus comprising:
- a) means for testing the plurality of storage locations in the MUT and generating fault signals indicating which of the plurality of storage locations in the MUT is faulty,b) a plurality of region modules, each said module having an input, and each said region module comprising;
i) a region fault RAM storing data,ii) analysis means, connected to said region fault RAM, for analyzing the data in the region fault RAM to identify faulty structures within the MUT, andiii) input means, coupled to the input of the region module and the region fault RAM, for storing information from the input to the region fault RAM, andc) interface means, having an input connected to the means for testing and a plurality of outputs, each output coupled to a region module, for routing fault signals indicating a faulty location to the input of a region module which is selected based on the region of the MUT which contains the faulty location.
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Accused Products
Abstract
Memory test apparatus including a redundancy analyzer with a catch RAM transfer interface circuit receiving fault information for a plurality of regions of a memory under test simultaneously in parallel and transmitting the information for each region to a respective one of a plurality of region modules that each has a region input circuit, a region fault RAM, and a microprocessor connected to have access to the region fault RAM, the region fault RAMs storing fault addresses identifying the locations of faults in the memory under test.
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Citations
28 Claims
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1. Memory test apparatus for testing a memory under test (MUT) formed from physical structures which define a plurality of storage locations organized into a plurality of regions, said apparatus comprising:
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a) means for testing the plurality of storage locations in the MUT and generating fault signals indicating which of the plurality of storage locations in the MUT is faulty, b) a plurality of region modules, each said module having an input, and each said region module comprising; i) a region fault RAM storing data, ii) analysis means, connected to said region fault RAM, for analyzing the data in the region fault RAM to identify faulty structures within the MUT, and iii) input means, coupled to the input of the region module and the region fault RAM, for storing information from the input to the region fault RAM, and c) interface means, having an input connected to the means for testing and a plurality of outputs, each output coupled to a region module, for routing fault signals indicating a faulty location to the input of a region module which is selected based on the region of the MUT which contains the faulty location. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A memory test apparatus for analyzing fault information for a memory under test (MUT), said apparatus comprising;
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a) a computer work station, b) means, connected to the computer work station and operating in response to commands from the computer work station, for generating fault information from said memory under test, c) a capture RAM connected to the means for generating fault information, d) at least one fault RAM connected to said capture RAM, e) means for transferring data from the capture RAM to the fault RAM, and f) microprocessor means, connected to have access to said fault RAM, for analyzing said MUT fault. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification