Nonvolatile memory
AssigneeFujitsu Limited
InventorKazunori KASUGA
Life of this patent
Estimating the term…
Abstract
A nonvolatile memory includes a memory cell allay including a plurality of memory cells, each of the memory cells capable of storing electric charges nonvolatilly, a first sense amplifier for comparing a voltage produced by one of the selected memory cells to be read out with a first threshold value for distinguishing between a write state and an erase state of the selected memory cell, a second sense amplifier for comparing the voltage produced by one of the selected memory cell with a second threshold value having a greater voltage than the first threshold voltage, and a write unit for rewriting data of the selected memory cell when the first and the second sense amplifiers produce different sense outputs from each other.
Claims20
A nonvolatile memory, comprising:
- a memory cell allay including a plurality of memory cells, each of the memory cells capable of storing electric charges nonvolatilly;
- a first sense amplifier for comparing a voltage produced by one of the selected memory cells to be read out with a first threshold value for distinguishing between a write state and an erase state of the selected memory cell;
- a second sense amplifier for comparing the voltage produced by one of the selected memory cell with a second threshold value having a greater voltage than the first threshold voltage;
- and
- a write unit for rewriting data of the selected memory cell when the first and the second sense amplifiers produce different sense outputs from each other.
A memory control unit, comprising:
- a nonvolatile memory including a memory cell allay including a plurality of memory cells, each of the memory cells capable of storing electric charges nonvolatilly, a first sense amplifier for comparing a voltage produced by one of the selected memory cells to be read out with a first threshold value for distinguishing between a write state and an erase state of the selected memory cell, a second sense amplifier for comparing the voltage produced by one of the selected memory cell with a second threshold value having a greater voltage than the first threshold voltage, and a write unit for rewriting data of the selected memory cell when the first and the second sense amplifiers produce different sense outputs from each other;
- and
- a write instruction unit for instructing to write the data of the selected memory cell when the first and the second sense amplifiers produce the different sense outputs from each other.
A memory control system, comprising:
- a memory control unit including a memory cell allay including a plurality of memory cells, each of the memory cells capable of storing electric charges nonvolatilly, a first sense amplifier for comparing a voltage produced by one of the selected memory cells to be read out of the floating gate with a first threshold value for distinguishing between a write state and an erase state of the selected memory cell, a second sense amplifier for comparing the voltage produced by one of the selected memory cell with a second threshold value having a greater voltage than the first threshold voltage, and a write unit for rewriting data of the selected memory cell when the first and the second sense amplifiers produce different sense outputs from each other, and a write instruction unit for instructing to write data of the selected memory cell when the first and the second sense amplifiers produce different sense outputs from each other;
- and
- a display control unit for displaying a state of an operation of the memory control unit on a display.
Dependencies are inferred from the claim text.