Flash memory and reading method of flash memory

摘要

A reading method of a flash memory, the reading method including: sensing hard data of a first target page by using a first hard read voltage; and generating soft data of the first target page by using at least one pair of, that is, two, first soft read voltages whose voltage levels are different from a voltage level of the first hard read voltage, while the flash memory performs a first operation on the hard data.

主权项

1. A reading method oaf MLC (Multi-Level Cell) flash memory, the reading method comprising:
receiving a first read-out command from a controller located out of the flash memory; generating hard data of a first page by using a first hard read voltage in response to the first read-out command; receiving a second read-out command from the controller; and generating soft data of the first page by using first soft read voltages in response to the second read-out command; wherein each of voltage levels of the first soft read voltages are set by modifying a voltage level of at least one second hard read voltage used for generating hard data of a second page; wherein the first page is a page in which each of memory cells is programmed to store a high-order bit of multi-bits, and the first hard read voltage is set to have two or more different voltage levels whose number corresponds to the number of the multi-bits; and wherein the generating of the soft data of the first page comprises:
transmitting to a first latch a first soft value that is obtained by sensing the first page by using one of the first soft read voltages corresponding to a first voltage level of the first hard read voltage, and transmitting to a second latch a third soft value, wherein the third soft value is obtained by cooking the first soft value of the first latch and a second soft value, wherein the second soft value is obtained by sensing the first page by using the other one of the first soft read voltages;transmitting to the first latch a first soft value that is obtained by sensing the first page by using one of second soft read voltages corresponding to a second voltage level of the first hard read voltage, and obtaining a third soft value of the second soft read voltages by cooking the first soft value of the first latch and a second soft value that is obtained by sensing the first page by using the other one of the second soft read voltages; andchanging the third soft value of the second latch by cooking the third soft value of the second soft read voltages and the third soft value previously stored in the second latch.