Macronix International Co., Ltd.

Chin Hung Chang

Chun Hsiung Hung

Wen Chiao Ho

Kuen-Long Chang

Kuen Long Chang

Yi Chun Shih

Cheng-Chi Liu

A method for determining read voltage margins in a memory array compares as-read sum codes generated from data read from the memory array with expected sum codes generated from the loaded data. The read voltage (Vt) is stepped and the as-read sum codes are compared to the expected sum codes to determine the Vt range(s) that provides matching sum codes. Multiple read voltage margins (i.e. the read voltage margins between multiple programming levels of the MLC memory array) are determined in a parallel fashion as Vt is stepped across its range.

Parallel threshold voltage margin search for MLC memory application

The present invention provides a novel method in altering the sequence of multi-level-cell programming in a multi-bit-cell of a nitride trapping memory cell that reduces or eliminates voltage threshold shifts between program steps while avoiding the suppression in the duration of a read window caused by a complementary bit disturbance. In a first embodiment, the present invention programs the multi-level cell in a multi-bit-cell having four bits in the following order: programming a third program level (level), programming a first program level (level) and a second program level (level) to level, and programming the second program level from the first program level. In a second embodiment, the present invention programs the multi-level cell in the multi-bit-cell having four bits in the following order: programming a third program level (level), programming a second program level (level), and programming a first program level (level).

Multi-level-cell programming methods of non-volatile memories

A method for operating a multi-level cell ('MLC') memory array of an integrated circuit ('IC') programs first data into a first plurality of MLCs in the MLC memory array at a first programming level. Threshold voltages for the first plurality of MLCs are sensed, and an adjust code is set according to the threshold voltages. Second data is programmed into a second plurality of MLCs in the MLC memory array at a second programming level, the second plurality of MLCs having a program-verify value set according to the adjust code. In a further embodiment, a reference voltage for reading the second plurality of MLCs is set according to the adjust code.

Dynamic program and read adjustment for multi-level cell memory array

A page mode program sequence is described that includes first and second bias applying cycles. In the first cycle, a program bias is applied to a first part of a page of memory cells, while a program verify bias is applied to, and data is sensed from, a second part of the page. In this manner, a first part of the page is programmed, while a second part of the page is verified. This operation is followed by a second bias applying cycle, in which a program bias is applied to the second part of the page, while a program verify bias is applied to, and data is sensed from, the first part of the page.

Nonvolatile memory with program while program verify

The present invention provides a novel method in altering the sequence of multi-level-cell programming in a multi-bit-cell of a nitride trapping memory cell that reduces or eliminates voltage threshold shifts between program steps while avoiding the suppression in the duration of a read window caused by a complementary bit disturbance. In a first embodiment, the present invention programs the multi-level cell in a multi-bit-cell having four bits in the following order: programming a third program level (level3), programming a first program level (level1) and a second program level (level2) to level 1, and programming the second program level from the first program level. In a second embodiment, the present invention programs the multi-level cell in the multi-bit-cell having four bits in the following order: programming a third program level (level3), programming a second program level (level2), and programming a first program level (level 1).

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Tainan, Taiwan

Chin Hung Chang