SYSTEM AND METHOD TO UPDATE READ VOLTAGES IN A NON-VOLATILE MEMORY IN RESPONSE TO TRACKING DATA

摘要

A storage device includes a read voltage engine (114) which is located either in a controller (112) or in a memory (104). Due to various effects such as data retention, read disturb, and/or program disturb, threshold voltages of data storage elements may shift, producing errors when read using the original set of read voltages. The read voltage engine (114) adjusts a read voltage to be used by the controller (112) to read data from the non-volatile memory (104). During operation, when data is to be read from the memory (104), such as when a request is received from the host device (116), the controller (112) may be configured to read a representation (122) of the tracking data (109) from at least a portion of the memory (104), such as the first portion (108). Over time the stored tracking data (109) may be susceptible to errors, resulting in the representation (122) of the tracking data (109) that may include one or more errors. The controller (112) may further compare a count of bits in the representation (122) of the tracking data (109) corresponding to storage elements in one or more states read from the memory (104) to a corresponding count of bits in the tracking data (109) and the read voltage engine (114) may be configured to adjust a read voltage to be used by the controller (112) to read data from the memory (104) based on the comparison.