Mapping for multi-state programming of memory devices
Storage device programming methods, systems and devices are described. A method may generate a mapping of data based on a set of data, the mapping of data including a first mapped data and a second mapped data. The method may include performing a first programming operation to write, in a first mode, the first mapped data to the memory device. The method may include storing the second mapped data to a cache. The method may include generating a second set of data, based on an inverse mapping of the mapping of data including the second mapped data from the cache and the first mapped data from the memory device, for writing, in a second mode, to the memory device, wherein the second set of data includes the set of data, and the first mode and the second mode correspond to different modes of writing to the memory device.
1. A storage system, comprising:
a first memory;
a second memory;
one or more controllers configured to cause:
writing, in a first mode, a first mapped data to the first memory;
storing a second mapped data to the second memory;
generating a combined set of data, represented by a set of balanced Gray codes, based on a combination of the first mapped data and the second mapped data, wherein the set of balanced Gray codes includes a sum of transitions that is not greater than a maximum number of read levels for writing in a second mode to the first memory; and
writing to the first memory, in the second mode, data based on the combined set of data.
2. The storage system of claim 1 ,
wherein the first mode and the second mode correspond to different modes of writing to the first memory, and
wherein the one or more controllers are configured to cause generating the combined set of data, based on an inverse mapping of the first mapped data and the second mapped data.
3. The storage system of claim 1 ,
wherein the first mapped data and the second mapped data are based on a first set of data;
wherein an amount of the first mapped data is greater than an amount of the second mapped data, and
wherein the combined set of data comprises the first set of data.
4. The storage system of claim 1 , wherein the one or more controllers are configured to cause:
generating a mapping of data based on a first set of data, the mapping of data including the first mapped data and the second mapped data,
wherein generating the mapping of data comprises:
generating the first mapped data and the second mapped data based on a Gray code encoding of the first set of data, and
wherein the first mapped data comprises a first plurality of data representable in rows and columns, the first plurality of data is represented by a plurality of balanced Gray codes, and the second mapped data comprises a second plurality of data.
5. The storage system of claim 4 , wherein:
the plurality of balanced Gray codes include a sum of transitions for each column, in the first plurality of data, wherein a total of the sums of the transitions for all of the columns is not greater than a maximum number of read levels for writing in the first mode to the first memory,
a sum of the transitions for one of the columns and a sum of the transitions for a next one of the columns are same or differ by not more than one, and
each of the transitions for a column represents a change in values between adjacent rows within the column.
6. The storage system of claim 4 , wherein data in every two rows of the first plurality of data are an identical pair.
7. The storage system of claim 1 , wherein a number of transitions for the first mapped data comprises seven transitions, wherein a number of transitions for the second mapped data comprises eight transitions, and wherein each transition corresponds to a change between neighboring data.
8. The storage system of claim 1 , wherein the first mapped data comprises at least a most significant bit (MSB), and the second mapped data comprises at least a least significant bit (LSB).
9. The storage system of claim 1 , wherein the one or more controllers are configured to cause:
performing a decoding operation to generate the data based on the combined set of data; and
performing a second programming operation to write, in the second mode, the data based on the combined set of data, to the first memory.
10. The storage system of claim 1 , wherein the first mode is related to programming for triple-level cell (TLC) memory, and the second mode is related to programming for quadruple-level cell (QLC) memory.
11. A method implemented using one or more controllers, the method comprising:
writing, in a first mode, a first mapped data to a first memory;
storing a second mapped data to a second memory;
generating a combined set of data, represented by a set of balanced Gray codes, based on a combination of the first mapped data and the second mapped data, wherein the set of balanced Gray codes includes a sum of transitions that is not greater than a maximum number of read levels for writing in a second mode to the first memory; and
writing to the first memory, in the second mode, data based on the combined set of data.
12. The method of claim 11 ,
wherein the first mode and the second mode correspond to different modes of writing to the first memory, and
wherein the combined set of data is generated, based on an inverse mapping of the first mapped data and the second mapped data.
13. The method of claim 11 ,
wherein the first mapped data and the second mapped data are based on a first set of data;
wherein an amount of the first mapped data is greater than an amount of the second mapped data, and
wherein the combined set of data comprises the first set of data.
14. The method of claim 11 , comprising:
generating a mapping of data based on a first set of data, the mapping of data including the first mapped data and the second mapped data,
wherein generating the mapping of data comprises:
generating the first mapped data and the second mapped data based on a Gray code encoding of the first set of data, and
wherein the first mapped data comprises a first plurality of data representable in rows and columns, the first plurality of data is represented by a plurality of balanced Gray codes, and the second mapped data comprises a second plurality of data.
15. The method of claim 14 , wherein:
the plurality of balanced Gray codes include a sum of transitions for each column, in the first plurality of data, wherein a total of the sums of the transitions for all of the columns is not greater than a maximum number of read levels for writing in the first mode to the first memory,
a sum of the transitions for one of the columns and a sum of the transitions for a next one of the columns are same or differ by not more than one, and
each of the transitions for a column represents a change in values between adjacent rows within the column.
16. The method of claim 14 , wherein data in every two rows of the first plurality of data are an identical pair.
17. The method of claim 11 , wherein a number of transitions for the first mapped data comprises seven transitions, wherein a number of transitions for the second mapped data comprises eight transitions, and wherein each transition corresponds to a change between neighboring data.
18. An apparatus, comprising:
means for writing, in a first mode, a first mapped data to a first memory;
means for storing a second mapped data to a second memory;
means for generating a combined set of data, represented by a set of balanced Gray codes, based on a combination of the first mapped data and the second mapped data, wherein the set of balanced Gray codes includes a sum of transitions that is not greater than a maximum number of read levels for writing in a second mode to the first memory; and
means for writing to the first memory, in the second mode, data based on the combined set of data.
19. The apparatus of claim 18 ,
wherein the first mode and the second mode correspond to different modes of writing to the first memory, and
wherein the combined set of data is generated, based on an inverse mapping of the first mapped data and the second mapped data.
20. The apparatus of claim 18 ,
wherein the first mapped data and the second mapped data are based on a first set of data;
wherein an amount of the first mapped data is greater than an amount of the second mapped data, and
wherein the combined set of data comprises the first set of data.