Emulating the aging of NAND Flash memories as a time-variant communications channel

The performance of NAND Flash memories, the most successful non-volatile memory technology today, deteriorates as the number of write accesses increases. This process, known as aging, is not only irreversible but also critical for the design of systems that are based on NAND Flash memories (ie. Solid-State Drives), since it affects the system´s IO performance and the required overhead for achieving a specific level of reliability. Experimental characterization of NAND Flash-based systems during their whole lifetime is a time-consuming and non-repeatable process, since further programming cycles increase aging, and the systems´ behavior changes. In this work, we present the architecture, along with experimental results, of a system that can be used to emulate in real-time and with high precision the behavior of NAND Flash memories under user-defined aging conditions. The system can be adjusted to the specific characteristics of any NAND technology and supports single-level and multi-level cells. The main advantages of this approach are the following: the emulated technology can be used under the same aging conditions for repetitive experiments and the same system can be used to compare different memory technologies at the system level and under different aging conditions using the same hardware setup.