摘要:
A non-volatile semiconductor memory device includes a memory cell array having a plurality of multi-level memory cells connected in series. The plurality of multi-level memory cells forms a plurality of threshold distributions each of which corresponds to a status of a lower bit and a status of an upper bit, wherein a lower bit and an upper bit constitute a lower page and an upper page respectively. The status of the lower bit dichotomizes the threshold distributions into two groups and the status of the upper bit further dichotomizes each of two groups. When programming a memory cell of the upper page, higher potentials are applied to a non-selected word line adjacent to the selected word line than those applied to the non-selected word line when programming the memory cell of the lower page.
摘要:
A non-volatile semiconductor memory device includes a memory cell array with electrically rewritable non-volatile memory cells laid out therein, an address selector circuit for performing memory cell selection of the memory cell array, a data read/write circuit arranged to perform data read of the memory cell array and data write to the memory cell array, and a control circuit for executing a series of copy write operations in such a manner that a data output operation of from the data read/write circuit to outside of a chip and a data write operation of from the data read/write circuit to the memory cell array are overlapped each other, the copy write operation including reading data at a certain address of the memory cell array into the data read/write circuit, outputting read data held in the read/write circuit to outside of the chip and writing write data into another address of the memory cell array, the write data being a modified version of the read data held in the data read/write circuit as externally created outside the chip.
摘要:
A non-volatile semiconductor device has a memory cell array having electrically erasable programmable non-volatile memory cells, reprogramming and retrieval circuits that temporarily store data to be programmed in the memory cell array and sense data retrieved from the memory cell array. Each reprogramming and retrieval circuit has first and second latches that are selectively connected to the memory cell array and transfer data. A controller controls the reprogramming and retrieval circuits on a data-reprogramming operation to and a data-retrieval operation from the memory cell array. Each reprogramming and retrieval circuit has a multilevel logical operation mode and a caching operation mode. In the multilevel logical operation mode, re-programming and retrieval of upper and lower bits of two-bit four-level data is performed using the first and the second latches to store the two-bit four-level data in one of the memory cells in a predetermined threshold level range. In the caching operation mode, data transfer between one of the memory cells selected in accordance with a first address and the first latch is performed while data transfer is performed between the second latch and input/output terminals in accordance with a second address with respect to one-bit two-level data to be stored in one of the memory cells.
摘要:
In a semiconductor integrated circuit, an internal circuit is capable of executing a first operation and a second operation concurrently, and an output circuit outputs to the outside of the semiconductor integrated circuit information indicating whether or not the first operation is being executed and information indicating whether or not the second operation is executable.
摘要:
According to an aspect of an embodiment, a method of manufacturing a photomask has forming a laminate over a transparent substrate, the laminate having a light-shielding layer and a hard mask layer, forming a negative resist layer over the laminate, exposing and developing the negative resist layer over the laminate to form a first resist pattern having a main pattern in a main exposure area surrounded by an outer area, etching the hard mask layer using the first resist pattern as an etching mask to form a hard mask pattern, removing the first resist pattern from the laminate; forming a positive resist layer covering the hard mask pattern over the transparent substrate, exposing and developing the positive resist layer to form a second resist pattern, the second resist pattern and a light-shielding pattern disposed in the outer area and forming an opening disclosing the hard mask pattern.
摘要:
The present invention provides a method for writing data to a non-volatile memory device having first wirings and second wirings intersecting one another and memory cells arranged at each intersection therebetween, each of the memory cells having a variable resistive element and a rectifying element connected in series. According to the method, the second wirings are charged to a certain voltage not less than a rectifying-element threshold value, prior to a rise in a selected first wiring. Then, a selected first wiring is charged to a voltage required for writing or erasing, after which a selected second wiring is discharged.
摘要:
A non-volatile semiconductor memory device including a NAND cell unit with a plurality of electrically rewritable and non-volatile memory cells connected in series, a source line coupled to one end of the NAND cell unit, and a bit line coupled to the other end of the NAND cell unit, wherein the NAND cell unit is biased in a data write mode as follows: a write voltage Vpgm is applied to a control gate of a selected memory cell in the NAND cell unit; a channel-isolating voltage is applied to control gates of non-selected memory cells disposed on the source line side of the selected memory cell at intervals of a certain number of memory cells; and a write medium voltage Vm lower than Vpgm is applied to control gates of the remaining non-selected memory cells.
摘要:
A threshold voltage read method of a nonvolatile semiconductor memory device is disclosed. The threshold voltage read method applies a first threshold voltage measuring read voltage to the word line with a selection gate kept in a nonconductive state and then makes the selection gate conductive to read out a threshold voltage of the first data at the time of reading out the threshold voltage of the first data. Then, it applies a second threshold voltage measuring read voltage to the word line with the selection gate kept in the conductive state to read out a threshold voltage of the second data at the time of reading out the threshold voltage of the second data.
摘要:
A nonvolatile semiconductor memory device having a first circuit for selecting one from the plurality of blocks, the first circuit having a plurality of transistors connected to word lines connected to some of the nonvolatile memory cells and a second circuit for generating a first voltage V1, a second voltage V2 and a third voltage V3 (V3
摘要:
A semiconductor memory device comprises a driver including a first resistor, and a control signal generator including a second resistor. A storage unit is employed to store adjustment data for setting a resistance of said second resistor at a designed resistance, which is specified based on the state of the control signal actually obtained when the resistance of the second resistor is set to a certain designed value. The storage unit is referred to for stored data to switch the second resistor to control the state of the control signal. In addition, the first resistor is switched to a resistance corresponding to the resistance of the second resistor.