Nonvolatile memory

Abstract

It is aimed to detect, notify, and save an abnormal area in semiconductor memory for greatly improving reliability. An inside of semiconductor memories provided for a memory card comprises a user area, a substitution area, an area substitution information storage area, and a management area. An inside of semiconductor memories comprises a user area, a substitution area, and a management area. The user area is a data area a user can use. The substitution area is substituted when an error occurs in the user area. The area substitution information storage area stores area substitution area information. The management area stores substitution information. The information processing section performs substitution on two levels as follows. When detecting an operation indicating a symptom of failure in a semiconductor memory area, the information processing section performs area substitution during an idle state of the memory card. When detecting a faulty operation in an area, the information processing section immediately performs area substitution.

1 . A storage device comprising one or more semiconductor memories and an information processing section which reads data stored in the one or more semiconductor memories based on an operating program and instructs a predetermined process and an operation to write data, 
 wherein the information processing section detects a state of an area in the semiconductor memory,    substitutes the area during an idle state causing no operations in the storage device when the area is assumed to be a critical state, and    substitutes the area immediately when the area is assumed to be a limit state.    
     
     
         2 - 10 . (canceled)