FPGA-based failure mode testing and analysis for MLC NAND flash memory

With the improvement of flash memory storage density, data reliability and flash lifetime are decreased. Error correction codes (ECC) and error management schemes can boost both reliability and lifetime. However, in order to develop effective fault tolerance algorithms and management solutions, it is very necessary to have a more profound understanding of failure modes of flash memory. To enable such understanding, we design an experimental platform and scheme to clearly investigate flash failure modes. This paper examines various failure modes occurring at 2x-nm MLC NAND flash technologies, such as page allocation scheme-based program interference (PASBPI) errors (i.e., different page allocation schemes mean data can be programmed into flash pages in different ways, which can lead to different program interference errors), write errors of the least significant bit (LSB) and the most significant bit (MSB) and different data pattern-based read interference errors (i.e., different data values programmed into flash pages can cause differential read interference errors). We analyze these observed failure modes and explain why they exist. We hope it is helpful to understand these discovered failure modes to propose effective fault tolerance and error management algorithms.