Verifying data integrity in a data storage device

A method of retrieving data from a device comprising:

• receiving an address for a memory location in the device;
• retrieving a value from a verification cell in the device associated with the memory location, the verification cell storing a predetermined value equal to a function of the address of the memory location;
• determining whether the retrieved value is an expected value equal to said function of the received address;
• and
• if the retrieved value is the expected value, providing a data value as a retrieved unit of data;
• and if the retrieved value is not the expected value, initiating a protective action.

A method of retrieving data from a device comprising:

• receiving an address corresponding to a memory location in a device;
• determining whether the device is in a secure mode or a bypass mode;
• if the device is in the secure mode, a) retrieving a value from a verification cell storing a predetermined value equal to a function of an address value associated with the verification cell;
• b) determining whether the retrieved value is an expected value equal to said function of the received address;
• and c) if the retrieved value is the expected value, providing a data value as a retrieved unit of data;
• and if the retrieved value is not the expected value, initiating a protective action;
• and
• if the device is in the bypass mode, providing a retrieved unit of data.

An article of manufacture comprising a non-transitory storage media containing instructions that, when executed by a controller, perform operations comprising:

• receiving an address corresponding to a memory location in a device;
• determining whether the device is in a secure mode or a bypass mode;
• if the device is in the secure mode, a) retrieving a value from a memory verification cell corresponding to the memory location, the verification cell storing a predetermined value equal to a function of an address value associated with the verification cell;
• b) determining whether the retrieved value is an expected value equal to said function of the received address;
• and c) if the retrieved value is the expected value, providing a data value as a retrieved unit of data, and if the retrieved value is not the expected value, initiating a protective action;
• and
• if the device is in the bypass mode, outputting a retrieved unit of data.