Method and apparatus for reducing silent data errors in non-volatile memory systems
In one embodiment, an apparatus comprises a memory array comprising a plurality of phase change memory (PCM) cells; and a controller to determine to read data stored by the plurality of PCM cells independent of a read command from a host device; and in response to the determination to read data stored by the plurality of PCM cells independent of a read command from a host device, perform a dummy read operation on the plurality of PCM cells and perform an additional read operation on the plurality of PCM cells.
1. An apparatus comprising:
a memory array comprising a plurality of phase change memory (PCM) cells; and
a controller to:
determine to read data stored by the plurality of PCM cells independent of a read command from a host device; and
in response to the determination to read data stored by the plurality of PCM cells independent of a read command from a host device:
perform a dummy read operation on the plurality of PCM cells;
perform an additional read operation on the plurality of PCM cells;
perform an error correction operation on data read by the additional read operation; and
write data corrected by the error correction operation into the plurality of PCM cells to overwrite the data read by the additional read operation.
2. The apparatus of claim 1 , the controller to discard data read during the dummy read operation.
3. The apparatus of claim 1 , the controller to discard data read by the dummy read operation after a determination that the data has passed an error correction operation.
4. The apparatus of claim 1 , the controller to write data read by the additional read operation into the plurality of PCM cells.
5. The apparatus of claim 1 , wherein performance of the dummy read operation comprises sensing the plurality of PCM cells and performing error correction on data sensed from the plurality of PCM cells.
6. The apparatus of claim 1 , the controller to:
perform error correction and a cyclic redundancy check on data read in response to a read command received from the host device; and
perform error correction but not perform a cyclic redundancy check on data read in response to the determination to read data stored by the plurality of PCM cells.
7. The apparatus of claim 1 , the controller to apply a plurality of demarcation voltages to the plurality of PCM cells during the dummy read operation.
8. The apparatus of claim 1 , the memory array comprising a three dimensional crosspoint memory array.
9. The apparatus of claim 1 , the controller to determine to read data stored by the plurality of PCM cells independent of a read command from a host device in response to a detection that the apparatus has been powered up.
10. The apparatus of claim 1 , the controller to determine to read data stored by the plurality of PCM cells independent of a read command from a host device in response to a detection that a raw bit error rate of a plurality of read operations has crossed a threshold.
11. The apparatus of claim 1 , wherein performance of the dummy read operation comprises performance of an XOR based data recovery operation.
12. The apparatus of claim 1 , further comprising a battery communicatively coupled to a processor, a display communicatively coupled to the processor, or a network interface communicatively coupled to the processor.
13. A method comprising:
determining to read data stored by a plurality of phase change memory (PCM) cells independent of a read command from a host device; and
in response to determining to read data stored by the plurality of memory cells independent of a read command from a host device:
performing a dummy read operation on the plurality of memory cells;
performing an additional read operation on the plurality of memory cells;
performing an error correction operation on data read by the additional read operation; and
writing data corrected by the error correction operation into the plurality of PCM cells to overwrite the data read by the additional read operation.
14. The method of claim 13 , further comprising discarding data read during the dummy read operation.
15. The method of claim 13 , further comprising writing data read by the additional read operation into the plurality of memory cells.
16. The method of claim 13 , further comprising, during performance of the dummy read operation, sensing the plurality of memory cells and performing error correction on data sensed from the plurality of memory cells.
17. A non-transitory machine readable storage medium having instructions stored thereon, the instructions when executed by a machine to cause the machine to:
determine to read data stored by a plurality of phase change memory (PCM) cells independent of a read command from a host device; and
in response to the determination to read data stored by the plurality of memory cells independent of a read command from a host device:
perform a dummy read operation on the plurality of memory cells;
perform an additional read operation on the plurality of memory cells;
perform an error correction operation on data read by the additional read operation; and
write data corrected by the error correction operation into the plurality of PCM cells to overwrite the data read by the additional read operation.
18. The medium of claim 17 , the instructions when executed to cause the machine to discard data read during the dummy read operation.
19. The medium of claim 17 , the instructions when executed to cause the machine to write data read by the additional read operation into the plurality of memory cells.
20. The medium of claim 17 , wherein performance of the dummy read operation comprises sensing the plurality of memory cells and performing error correction on data sensed from the plurality of memory cells.
21. A system comprising:
a controller to:
determine to read data stored by a plurality of phase change memory (PCM) cells of an array independent of a read command from a host device; and
in response to the determination to read data stored by the plurality of memory cells of the array independent of a read command from a host device:
perform a dummy read operation on the plurality of memory cells;
perform an additional read operation on the plurality of memory cells;
perform an error correction operation on data read by the additional read operation; and
write data corrected by the error correction operation into the plurality of PCM cells to overwrite the data read by the additional read operation.
22. The system of claim 21 , further comprising the plurality of PCM cells.
23. The system of claim 21 , further comprising a central processing unit of the host device, the central processing unit to send a read command to the controller.
24. The system of claim 23 , further comprising a battery communicatively coupled to the central processing unit, a display communicatively coupled to the central processing unit, or a network interface communicatively coupled to the central processing unit.