After completing operation 564, method 500 advances to decision 566 which determines whether the write procedure of operation 564 was performed successfully. When decision 566 determines that one or more write error occurs during the write procedure (the write procedure was unsuccessful), method 500 proceeds to operation 508 whereby the result of the re-evaluation is to retire the unit of memory from any future use. An unsuccessful write procedure may result when a number of write errors for one or more of the subunits of the unit of memory is greater than an accepted threshold.

However, when decision 566 determines the write procedure was successful, method 500 proceeds to operation 568 which includes performing a calibration of the unit of memory. According to different approaches, the success of the write procedure may correspond to situations in which no write errors occur during the write procedure, a number of write errors below a given threshold occur during the write procedure, etc.

As previously mentioned, operation 568 includes performing a calibration of the unit of memory. The process of calibrating the unit of memory may include, but is in no way limited to, determining the optimal threshold voltage shift values. Implementing the optimal threshold voltage shift values may consequently minimize the number of errors encountered upon performing a read operation on the unit of memory. Thus, it is preferred that a unit of memory is calibrated before being read.