BIASING SCHEMES FOR STORAGE OF BITS IN UNRELIABLE STORAGE LOCATIONS

摘要

A controller of a non-volatile memory system may be configured to identify bits of data to be stored in memory elements of non-volatile memory that are identified as unreliable. The controller may be configured to bias at least some of these bits to a predetermined logic value at which the bits are likely to be read from the unreliable memory elements. The controller may do so using a biasing key that the controller generates based on identification of the bits. Subsequently, when the data is read, the controller may assign log likelihood ratio values for the bits to correspond to a percent likelihood of the bits being biased to the predetermined logic value. The bits may also be unbiased using the biasing key.

主权项

1. A non-volatile memory system comprising:
non-volatile memory; an unreliable storage location identifier module configured to:
identify a plurality of memory elements of the non-volatile memory to store data;determine which memory elements of the plurality of memory elements are identified in the non-volatile memory system as unreliable; a biasing module configured to bias bits of the data to be stored in the identified unreliable memory elements to a predetermined logic value using a biasing key; and a biasing key generator module configured to assign bit values for the biasing key in order for the biasing module to bias, using the biasing key, more than 50% of the bits to be stored in the identified unreliable memory elements to the predetermined logic value.