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US 2002/0001233 A1Published application
Read protection circuit of nonvolatile memory
AssigneeSanyo Electric Co., Ltd.
InventorKazuo Hotaka
Life of this patent
Estimating the term…
Abstract
A read protection memory area is formed within the same memory mat as a main memory area, so that the need to dedicatedly provide a dedicated EEPROM cell for storing read protection data and an analog control circuit for writing the read protection data into this EEPROM cell is eliminated and a chip size can be reduced.
Claims5
A read protection circuit of nonvolatile memory, comprising:
- a main memory area including nonvolatile memories capable of electrically writing and reading, and the main memory area is provided in a memory mat;
- a read protection memory area provided within the same memory mat as the main memory area;
- a writing unit for writing read protection data including information as to whether read protection is provided into the read protection memory area;
- a reading unit for reading the read protection data stored in the read protection memory area according to a trigger signal,
- a register for temporarily storing the read protection data read from the read protection memory area;
- and
- a gate for setting a data output read from the main memory area in a read protected state according to output data of the register.
4 more elements
A read protection circuit of nonvolatile memory, comprising:
- a main memory area including nonvolatile memories capable of electrically writing and reading, and the main memory area is provided in a memory mat;
- a read protection memory area which is provided within the same memory mat as the main memory area and stores read protection data including information as to whether read protection is provided,
- a read protection control circuit for outputting a control signal for reading the read protection data stored in the read protection memory area according to a trigger signal,
- a register for temporarily storing the read protection data read from the read protection memory area, and
- a gate for setting a data output read from the main memory area in a read protected state according to output data of the register.
2 more elements
Dependencies are inferred from the claim text.