K-Partition flash code with BIFC-based sharing and some variants

Date of Award


Document Type


Degree Name

Doctor of Philosophy in Computer Science


Information Systems & Computer Science


  • Flash memory has a wide variety of applications nowadays. The information from flash devices are retrieved and stored through flash codes. The performance of a flash code is usually described in terms of its write deficiency. Flash codes with lower write deficiency provide a better performance that extends the lifespan of flash memory which is basically constrained by two technological issues: the write asymmetry in the flash cells and the limited program-erase cycles in the cell blocks. Related studies on flash codes in literature were investigated and analyzed with regards to their performance. The strengths of some flash codes that perform better in various frequency distributions were studied and considered. In this study, some elegant coding schemes are proposed that may help mitigate the flash constraints by efficiently performing cell writes in order to delay the occurrence of block erasures. Analytical investigations are conducted to derive the theoretical worst case write deficiency and then computer simulations are used to estimate the average case. Theoretical results and computer simulations show that the proposed flash codes are competitive to existing flash codes in literature. In the practical aspect, the implementation of these proposed coding schemes in flash memories can help prolong the lifespan of flash devices.


The C7.O77 2015