Semiconductor memory, method of testing semiconductor memory, and method of manufacturing semiconductor memory
First Claim
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1. A semiconductor memory comprising:
- a memory circuit; and
a testing circuit including a comparator for comparing data read from the memory circuit with expected value data to thereby detect coincidences/non-coincidences therebetween and a counter for counting the number of the detected non-coincidences, said memory circuit, said testing circuit, and a result-of-determination storage circuit storing a result of failure determination based on a result of comparison by the comparator being formed over the same semiconductor chip, wherein the memory circuit is tested by the testing circuit while addresses are being updated, the number of addresses at which failures are detected, is configured so as to be counted by the counter, and information obtained by ORing a previous result of failure determination read from the result-of-determination storage circuit with a result of failure/non-failure determination based on the result of comparison by the comparator is configured so as to be stored in the result-of-determination storage circuit.
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Abstract
Testing circuits each including a comparator for comparing data read from semiconductor memories to be tested with expected value data and thereby detecting coincidences/non-coincidences, and a counter for counting the number of non-coincidences detected are provided on a printed board for burn-in or within semiconductor memories to be tested. The semiconductor memories can be tested by the testing circuits respectively.
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Citations
7 Claims
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1. A semiconductor memory comprising:
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a memory circuit; and
a testing circuit including a comparator for comparing data read from the memory circuit with expected value data to thereby detect coincidences/non-coincidences therebetween and a counter for counting the number of the detected non-coincidences, said memory circuit, said testing circuit, and a result-of-determination storage circuit storing a result of failure determination based on a result of comparison by the comparator being formed over the same semiconductor chip, wherein the memory circuit is tested by the testing circuit while addresses are being updated, the number of addresses at which failures are detected, is configured so as to be counted by the counter, and information obtained by ORing a previous result of failure determination read from the result-of-determination storage circuit with a result of failure/non-failure determination based on the result of comparison by the comparator is configured so as to be stored in the result-of-determination storage circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification