Method and apparatus for protection of non-volatile memory in presence of out-of-specification operating voltage

A method of operating a memory device, the method comprising:

• receiving a data pattern as a known value;
• receiving a positive integer, N;
• reading the data pattern from the memory device N times to generate a plurality of test-read results;
• comparing each of the test-read results with the known value;
• and
• inhibiting the write command when one or more of the test-read results differ from the known value.

A memory system adapted to process read and write commands from a user processing unit, the memory system comprising:

• a memory array having a reference data pattern stored therein;
• and
• a memory controller coupled to the memory array and to the user processing unit, the memory controller comprising:
• a control unit adapted to receive the read and write commands, write data into and read data from the memory array according to the read and write commands, and read the reference data pattern as a test-read result;
• and
• a comparator coupled to the control unit, the comparator adapted to receive from the control unit the test-read result and the known value and to send to the control unit a comparison signal according to a difference between the test-read result and the known value, the control unit being further adapted to inhibit a write command when the comparison signal indicates a non-null difference between the test-read result and the known value.