Abstract—Flash memory is a good candidate for the storage device in real-time systems due to its non-fluctuating performance, low power consumption and high shock resistance. However, the garbage collection for invalid pages in flash memory can invoke a long blocking time. Moreover, the worst-case blocking time is significantly long compared to the best-case blocking time under the current flash management techniques. In this paper, we propose a novel flash translation layer (FTL), called KAST, where user can configure the maximum log block associativity to control the worst-case blocking time. Performance evaluation using simulations shows that the overall performance of KAST is better than the current FTL schemes as well as KAST guarantees the longest block time is shorter than the specified value.