caa a22 4500 606206574 CHVBK 20210128101012.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s00034-014-9869-3 doi (NATIONALLICENCE)springer-10.1007/s00034-014-9869-3 On the Case of Using Aggregated Page Programming for Future MLC NAND Flash Memory [Elektronische Daten] [Wenzhe Zhao, Guiqiang Dong, Hui Han, Nanning Zheng, Tong Zhang] Multi-level per cell (MLC) technique has been widely used to improve the storage density of NAND flash memory. In current design practice, bits stored in one cell are mapped to different pages, and all pages are protected with the same error correction code (ECC). However, those bits in one MLC flash memory cell have different error rates, and such unbalance increases with the number of bits in one cell. To guarantee the storage integrity, ECC should be tuned to cover the worst case page, which results in over-protection and redundancy waste for other pages and hence reduces storage capacity. This bit-to-cell mapping scheme also limit the number of bits in one cell to be integer. This paper proposes an aggregated page programming scheme, which maps all bits in one cell into the same page, to balance all pages to experience the same but lower overall bit error rates, so that the weaker ECC with higher coding rate can be employed. Furthermore, the noise margin of NAND flash memory cell decreases with program/erase cycling. To exploit such noise margin dynamics, this paper proposes to accommodate more storage levels in one cell during its early lifetime and dynamically modulate the number of storage levels to increase the overall effective storage capacity. Not-a-power-of-2 storage levels in one cell should be used to exploit the storage capacity aggressively, which can be enabled through proposed aggregated page programming scheme. Simulation results show the program capacity can be increased by more than 50%. Springer Science+Business Media New York, 2014 NAND flash nationallicence Flash channel nationallicence Unbalanced error rates nationallicence Aggregated page programming nationallicence Zhao Wenzhe Xi'an Jiaotong University, 710049, Xi'an, Shaanxi, People's Republic of China aut Dong Guiqiang Skyera Inc., 1704 Automation Pkwy, 95131, San Jose, CA, USA aut Han Hui Chongqing Communication Institute, 400035, Chongqing, People's Republic of China aut Zheng Nanning Xi'an Jiaotong University, 710049, Xi'an, Shaanxi, People's Republic of China aut Zhang Tong Rensselaer Polytechnic Institute, 12180, Troy, NY, USA aut Circuits, Systems, and Signal Processing Springer US; http://www.springer-ny.com 34/2(2015-02-01), 557-577 0278-081X 34:2<557 2015 34 34 https://doi.org/10.1007/s00034-014-9869-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00034-014-9869-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhao Wenzhe Xi'an Jiaotong University, 710049, Xi'an, Shaanxi, People's Republic of China aut NATIONALLICENCE 700 1- Dong Guiqiang Skyera Inc., 1704 Automation Pkwy, 95131, San Jose, CA, USA aut NATIONALLICENCE 700 1- Han Hui Chongqing Communication Institute, 400035, Chongqing, People's Republic of China aut NATIONALLICENCE 700 1- Zheng Nanning Xi'an Jiaotong University, 710049, Xi'an, Shaanxi, People's Republic of China aut NATIONALLICENCE 700 1- Zhang Tong Rensselaer Polytechnic Institute, 12180, Troy, NY, USA aut NATIONALLICENCE 773 0- Circuits, Systems, and Signal Processing Springer US; http://www.springer-ny.com 34/2(2015-02-01), 557-577 0278-081X 34:2<557 2015 34 34