Nonvolatile memory and semiconductor device
First Claim
1. A nonvolatile memory comprising:
- a memory array having a plurality of nonvolatile memory elements which store data according to magnitudes of threshold voltages thereof;
a booster circuit which generates a voltage applied to each of the nonvolatile memory elements upon writing or erasing of the data;
a boosted voltage detecting circuit which detects the level of the voltage boosted by the booster circuit;
a write/erase control circuit which starts the writing or erasing based on the detection of the voltage by the boosted voltage detecting circuit;
a write/erase end detecting circuit which detects the completion of the writing or erasing started by the write/erase control circuit; and
an end flag indicative of the completion of the writing or erasing started by the write/erase control circuit.
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Accused Products
Abstract
The invention includes a control register (CRG) for providing instructions as to basic operations such as writing, erasing, reading, etc., a boosted voltage attainment detecting circuit for detecting whether a voltage boosted by a booster circuit has reached a desired level, a circuit which counts the time required to apply each of write and erase voltages, and a circuit which detects the completion of the writing or erasing. Respective operations are automatically advanced by simple setting of the operation instructions to the control register. After the completion of the operations, an end flag (FLAG) provided within the control register is set to notify the completion of the writing or erasing.
211 Citations
23 Claims
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1. A nonvolatile memory comprising:
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a memory array having a plurality of nonvolatile memory elements which store data according to magnitudes of threshold voltages thereof;
a booster circuit which generates a voltage applied to each of the nonvolatile memory elements upon writing or erasing of the data;
a boosted voltage detecting circuit which detects the level of the voltage boosted by the booster circuit;
a write/erase control circuit which starts the writing or erasing based on the detection of the voltage by the boosted voltage detecting circuit;
a write/erase end detecting circuit which detects the completion of the writing or erasing started by the write/erase control circuit; and
an end flag indicative of the completion of the writing or erasing started by the write/erase control circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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13. A semiconductor device incorporating therein:
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a nonvolatile memory having a plurality of nonvolatile memory elements which store data according to the magnitudes of threshold voltages thereof;
a booster circuit which generates a voltage applied to each of the nonvolatile memory elements upon writing or erasing of the data;
a boosted voltage detecting circuit which detects the level of the voltage boosted by the booster circuit;
a write/erase control circuit which starts the writing or erasing based on the detection of the voltage by the boosted voltage detecting circuit;
a write/erase end detecting circuit which detects the completion of the writing or erasing started by the write/erase control circuit;
an end flag indicative of the completion of the writing or erasing started by the write/erase control circuit;
a control register having control bits each indicative of an entry into an operation for the writing or erasing; and
a control circuit for giving instructions as to any of the writing, erasing and reading to the nonvolatile memory according to the setting of the control bits of the control register.
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Specification