Multi-bit flash memory and reading method thereof
AssigneeMacronix International Co., Ltd.
InventorsYung-Feng Lin, Nian-Kai Zous, I-Jen Huang, Yin-Jen Chen
Life of this patent
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Abstract
A multi-bit flash memory and a reading method thereof. Multiple reference memory cells for saving reserved data are provided to operate together with multiple data memory cells. Before the data memory cells are read, data stored in the reference memory cell is sensed based on a present reference current. Then, a value of a new reference current for reading the data memory cells is determined according to a difference between the sensed data and the reserved data.
Claims13
A multi-bit memory, comprising:
- a plurality of data memory cells to be altered together;
- a plurality of reference memory cells for storing reserved data, wherein the reference memory cells are altered together along with the data memory cells;
- and
- a sensing component connected to the data memory cells and the reference memory cells, wherein the sensing component senses data stored in the reference memory cells based on a reference current to determine a new reference current for reading the data memory cells.
A method of reading a multi-bit flash memory having a plurality of data memory cells to be changed data together, the method comprising the steps of:
- sensing data stored in a plurality of reference memory cells based on a present reference current, wherein the reference memory cells are used for saving reserved data and are changed data together with the data memory cells;
- and
- determining a value of a new reference current for reading the data memory cells according to a difference between the data sensed from the reference memory cells and the reserved data.
A method of reading a multi-bit flash memory having a plurality of data memory cells to be changed data together, the method comprising the steps of:
- sensing data stored in a plurality of reference memory cells based on a present reference current, wherein the reference memory cells are used for saving reserved data and are changed data together with the data memory cells;
- comparing the data sensed from the reference memory cells with the reserved data to obtain a difference;
- adjusting, if the difference exists, a value of the reference current according to the difference until the data, which is stored in the reference memory cells sensed based on the adjusted reference current, matches with the reserved data;
- and
- reading the data memory cells based on the adjusted reference current.
Dependencies are inferred from the claim text.