ENCODING METHOD AND MEMORY DEVICE

摘要

This invention relates to a memory apparatus or the like adaptable to a multi-value recording flash memory and others. A flash memory 10 is designed for 16-value (4-bit) recording. For a write operation, the encoder (12) converts input data Din into an abbreviated Reed-Solomon code to provide write data WD. The converter (13) converts the write data WD into four-bit parallel data. The converted data are fed and written to the each memory cell constituting cell arrays (11) successively. For a read operation, the converter (14) converts read data RD from the cell arrays (11) into one-byte (8-bit) parallel data and supplies the converted data to the decoder (15) for error correction in units of bytes, whereby output data Dout is obtained. Since the Reed-Solomon code is used, sufficient performance with a limited number of errors to be corrected can be obtained.