READ METHOD OF FLASH MEMORY

摘要

In the present invention, disclosed is a method for reading a flash memory for reading multi-bit data stored in a memory cell. The method for reading a flash memory includes the steps of: performing the hard decision decoding on read data outputted from a flash memory; and performing the soft decision decoding on the read data if the hard decision decoding is not possible. The soft decision decoding step is performed by changing the maximum iteration number according to the threshold voltage distribution of memory cells. The hard decision and soft decision decoding steps are performed by changing the maximum iteration number of the hard decision decoding and the soft decision decoding according to success rates of hard decision and soft decision decoding stages.