Nino A. Salazar’s research while affiliated with Ateneo de Manila University and other places

This paper proposes a novel coding scheme which can extend the lifespan of flash memory. Flash memory has a number of advantages against conventional storage devices, but it must be noted that the flash cells which constitute a flash memory accommodate, not a small, but limited number of operations only. A flash code provides a clever way to represent data values in flash memory so that the number of operations over flash cells becomes as small as possible, and this contributes to extend the lifespan of flash memory. Several flash codes have been studied so far, and this paper proposes a novel coding scheme which makes use of two different modes of encoding. Computer simulation shows that the proposed coding scheme shows much better average-case performance than existing codes. Besides the computer simulation, the paper also gives detailed analysis of the performance which justifies the advantage of the proposed code from a more theoretical viewpoint.

A new flash code is proposed in this paper. This flash code has two modes of encoding: one extending the binary-indexed flash code which has been proposed by the authors, and the other using a simple mapping. It is shown that the proposed flash code has O(kq\log k + n) worst-case write deficiency, but competes very well with existing flash codes in the average write deficiency which is evaluated through computer simulations.