Flash quality and how this can be shown with the retention data have been discussed. The high retention that was documented does not come without a cost. Several firmware features are necessary to enable this high retention. Swissbit calls this “data care management” and it ensures that data has an optimum quality, independent of whether it has been frequently written or if it is read-only. It is dependent on the number of bit errors per page critical blocks that are refreshed. This is either initiated by a read access, or as a background process that scans the complete flash array and refreshes pages that show weaknesses. The triggers for these processes are defined by Swissbit according to technology characterization. If a page shows an uncorrectable number of bit errors, it is read again with different internal reference voltage settings. This read retry recovers even pages that seem to be unreadable.