Eeprom backup method and device

The method of claim 2, further comprising, in a second erase and program cycle after the first erase and program cycle:

• performing a program operation to store a second data in the second data area;
• after completion of the program operation, setting the second data area to a valid state, and performing an erase operation in the first data area;
• and
• after completion of the erase operation, setting the first data area to an erased state.

An electrically erasable programmable read-only memory (EEPROM) device, comprising:

• a plurality of data areas in the EEPROM associated with a corresponding plurality of memory addresses, respectively;
• a data status indicator associated with each of the plurality of data areas, the data status indicator configured to indicate that a data area is in an erase state, an uncertain state, or a valid state;
• and
• a controller;
• wherein a first data area and a second data area are configured to be a backup storage area for each other;
• wherein, in an erase and program cycle, at least one of the first or second memory areas is in a valid state throughout the erase and program cycle;
• and
• wherein, in an erase and program cycle, an erase operation is performed in one of the first or second memory areas, and a program operation is performed in the other data areas.

An electrically erasable programmable read-only memory (EEPROM) device, comprising:

• a plurality of data areas in the EEPROM associated with a corresponding plurality of memory addresses, respectively;
• a data status indicator associated with each of the plurality of data areas, the data status indicator configured to indicate that a data area is in an erase state, an uncertain state, or a valid state;
• a sequence number associated with each of the plurality of data areas;
• and
• a controller;
• wherein the EEPROM device is configured such that:
• during an erase operation, a data area is in an uncertain state and after completion of the erase operation, the data area is in an erased state;
• and
• during a program operation, the data area is in an uncertain state and after completion of the program operation, the data area is in a valid state;
• wherein the EEPROM device is further configured to, in a single erase and program cycle:
• perform a program operation in a first data area that is in an erase state;
• and
• after the program operation is completed, perform an erase operation in a second data area that is in a valid state.
• wherein the EEPROM is configured such that at least one of the first or second memory areas is in a valid state throughout the single erase and program cycle.