US 2008/0189588 A1 · BIT ERROR PREVENTION METHOD AND INFORMATION PROCESSING APPARATUS

Abstract

Whether the comparison value of temporarily stored data which is read out from a flash memory by a host system exceeds a threshold value related to a bit error or not is checked, and if the comparison value exceeds the threshold value, the temporarily stored data which is read out is rewritten into the flash memory. If the temporarily stored data has an error, the error is corrected by an error correction part and then the data is rewritten. The threshold value includes, e.g., the number of readouts, the number of bit errors and the number of accumulated occurrences of bit errors. The present invention is suitable for prevention of bit errors due to read disturb and can recover the bit data which changes with time, and therefore makes it possible to improve the reliability of the flash memory by preventing occurrence of bit errors.

Claims20

Dependent claims

A bit error prevention method of preventing a bit error which is caused by a change of bit data stored in a rewritable nonvolatile semiconductor memory, comprising:

a condition judgment step of judging whether a repair condition related to the bit error is satisfied or not when stored data which is stored in said nonvolatile semiconductor memory is read out by a host system;
and
a recovery step of rewriting said stored data which is read out in said nonvolatile semiconductor memory if said stored data which is read out satisfies said repair condition.

An information processing apparatus, comprising:

a rewritable nonvolatile semiconductor memory;
a read part for reading stored data which is stored in said nonvolatile semiconductor memory;
a condition judgment part for checking if said stored data to be read out by said read part satisfies a repair condition related to a bit error;
and
a recovery part for rewriting said stored data which is read out into said nonvolatile semiconductor memory if said stored data which is read out satisfies said repair condition.

2 more elements

Dependencies are inferred from the claim text.

Bit error prevention method and information processing apparatus

Life of this patent

Bit error prevention method and information processing apparatus

Life of this patent

Abstract

Claims20