Error correction code memory
An error-correction code memory includes memory locations for storing data. The memory is programmed to store one or more intentionally invalid words. Testing of an error correction circuit for the memory is performed by accessing the one or more intentionally invalid words and performing an error detection and error correction operation.
1. A method, comprising:
writing at least one intentionally invalid word into a first portion of an error-correction code memory; and
locking the first portion of the error-correction code memory in a read-only mode of access such that it is forbidden to write again to said first portion.
2. The method of claim 1 , further comprising, before said writing, generating said at least one intentionally invalid word.
3. The method of claim 1 , wherein writing at least one intentionally invalid word comprises writing a plurality of intentionally invalid words into the first portion, and further comprising, before said writing, selecting consecutive locations in the first portion of the error-correction code memory storing said plurality of intentionally invalid words.
4. The method of claim 1 , wherein said at least one intentionally invalid word comprises a single invalid bit.
5. The method of claim 1 , wherein said at least one intentionally invalid word comprises exactly two invalid bits.
6. The method of claim 1 , further comprising:
reading the at least one intentionally invalid word from the first portion of the error-correction code memory; and
processing the at least one intentionally invalid word to detect and correct error in order to confirm proper operation an error detection and correction function.
7. The method of claim 1 , further comprising testing operation of an error detection and correction by reading the at least one intentionally invalid word from the first portion of the error-correction code memory and processing the least one intentionally invalid word to detect and correct error due to the intentional invalidity of the word.
8. The method of claim 1 , wherein writing the at least one intentionally invalid word comprises writing the at least one intentionally invalid word into the first portion of the error-correction code memory in a factory at manufacture of the memory.
9. An apparatus, comprising:
an error-correction code memory, comprising:
a first memory portion including at least one memory location;
wherein the at least one memory location stores an intentionally invalid word; and
wherein the first memory portion is locked in a read-only mode of access such that it is forbidden to write to said first memory portion after storing of the intentionally invalid word.
10. The apparatus of claim 9 , wherein said at least one memory location comprises a plurality of memory locations, each memory location storing an intentionally invalid word.
11. The apparatus of claim 10 , wherein the plurality of memory locations are consecutive memory locations in the first memory portion.
12. The apparatus of claim 9 , wherein said intentionally invalid word comprises a single invalid bit.
13. The apparatus of claim 9 , wherein said intentionally invalid word comprises exactly two invalid bits.
14. The apparatus of claim 9 , wherein said intentionally invalid word is used to test an error correction circuit.
15. The apparatus of claim 9 , further comprising an error correction circuit configured to retrieve the intentionally invalid word from the first memory portion and process the intentionally invalid word to detect and correct error due to the intentional invalidity of the word in order to test functionality of the error correction circuit.
16. The apparatus of claim 9 , further comprising a circuit configured to write words into a second portion of the error-correction code memory.
17. The apparatus of claim 9 , further comprising an error correction circuit configured to retrieve words from the second memory portion and process the words to detect and correct error.
18. The apparatus of claim 9 , wherein the intentionally invalid word is written in the first memory portion in a factory at manufacture of the error-correction code memory.
19. An error-correction code memory, comprising:
a first memory portion including at least one memory location;
wherein the at least one memory location stores an intentionally invalid word; and
wherein the first memory portion is locked in a read-only mode of access such that it is forbidden to write to said first memory portion after storing of said intentionally invalid word.
20. The error-correction code memory of claim 19 , wherein said at least one memory location comprises a plurality of memory locations, each memory location storing an intentionally invalid word.
21. The error-correction code memory of claim 20 , wherein the plurality of memory locations are consecutive memory locations in the first memory portion.
22. The error-correction code memory of claim 19 , wherein said intentionally invalid word comprises a single invalid bit.
23. The error-correction code memory of claim 19 , wherein said intentionally invalid word comprises exactly two invalid bits.
24. The error-correction code memory of claim 19 , wherein said intentionally invalid word is used to test an error correction circuit.
25. The error-correction code memory of claim 19 , wherein the intentionally invalid word is written in the first memory portion in a factory at manufacture of the error-correction code memory.
26. A method, comprising:
writing data into a first portion of an error-correction code memory, said data comprising a bootloader program and at least one intentionally invalid word; and
then locking the first portion of the error-correction code memory in a read-only mode of access which forbids further writing of data into said first portion.
27. The method of claim 26 , further comprising:
reading the at least one intentionally invalid word from the first portion of the error-correction code memory; and
processing the at least one intentionally invalid word to detect and correct error in order to confirm proper operation an error detection and correction function.
28. The method of claim 26 , wherein writing data comprises writing the bootloader program and the at least one intentionally invalid word into the first portion of the error-correction code memory in a factory at manufacture of the memory.
29. A circuit, comprising:
an error-correction code memory, comprising:
a first memory portion including memory locations storing data, wherein said data comprises a bootloader program and at least one intentionally invalid word; and
a second memory portion; and
wherein the first memory portion is locked in a read-only mode of access which forbids writing of data into said first memory portion.
30. The circuit of claim 29 , further comprising an error correction circuit configured to retrieve the intentionally invalid word from the first memory portion and process the intentionally invalid word to detect and correct error due to the intentional invalidity of the word in order to test functionality of the error correction circuit.
31. The circuit of claim 29 , wherein the bootloader program and the intentionally invalid word are written in the first memory portion in a factory at manufacture of the error-correction code memory.