Error correction for flash memory
Systems and methods are disclosed to detect and correct errors in a flash memory by detecting in hardware an error based on one of three selectable modes of error detection and correction; and correcting the error by executing error correction software corresponding to the selected mode of error detection and correction.
1. A system to detect and correct errors in a flash memory, comprising:
at least three error detection circuits corresponding to three selectable error detection modes, the error detection circuits being adapted to detect an error based on a selected mode of error detection and correction; and
a processor coupled to the three error detection circuits, the processor adapted to correct the error by executing error correction software based on the selected mode.
2. The system of claim 1 , wherein the flash memory comprises an extra storage area and wherein the three modes of error detection and correction further comprises a first mode to correct one error, a second mode to correct two errors including errors in the extra storage area, and a third mode to correct three errors including errors in the extra storage area.
3. The system of claim 2 , wherein the first mode protects against any one symbol error.
4. The system of claim 3 , wherein the first mode comprises a Smart Media compatible mode.
5. The system of claim 2 , wherein the second mode protects against any two symbol errors, including those in the extra storage area.
6. The system of claim 5 , wherein the second mode further comprises a Reed-Solomon 52 (RS-52) mode.
7. The system of claim 2 , wherein the third mode protects against any three symbol errors, including those in the extra storage area.
8. The system of claim 7 , wherein the third mode further comprises an RS-73 mode.
9. The system of claim 8 , wherein the third mode utilizes the last eight bytes of the page as parity.
10. The system of claim 8 , wherein the third mode utilizes byte 520 through byte 527 as parity.
11. A method to detect and correct errors in a flash memory, comprising:
detecting an error based on a selected mode of error detection and correction using three error detection means corresponding to three selectable modes of error detection and correction; and
correcting the error by executing error correction software corresponding to the selected mode of error detection and correction.
12. The method of claim 11 , wherein the flash memory comprises an extra storage area and wherein the three modes of error detection and correction further comprises a first mode to correct one error, a second mode to correct two errors including errors in the extra storage area, and a third mode to correct three errors including errors in the extra storage area.
13. The method of claim 12 , wherein the first mode protects against any one symbol error.
14. The method of claim 13 , wherein the first mode comprises a Smart Media compatible mode.
15. The method of claim 12 , wherein the second mode protects against any two symbol errors, including those in the extra storage area.
16. The method of claim 15 , wherein the second mode further comprises a Reed-Solomon 52 (RS-52) mode.
17. The method of claim 12 , wherein the third mode protects against any three symbol errors, including those in the extra storage area.
18. The method of claim 17 , wherein the third mode further comprises an RS-73 mode.
19. The method of claim 18 , wherein the third mode utilizes the last eight bytes of the page as parity.
20. The method of claim 18 , wherein the third mode utilizes byte 520 through byte 527 as parity.