Before diving into the "6698-BB," it is crucial to understand the maker. (commonly abbreviated as 3S or SMI) is a fabless semiconductor company based in Taiwan. They are one of the "big three" controller manufacturers alongside Phison and Silicon Motion (note: despite the similar acronym, 3S is distinct from SMI).
It distributes write operations evenly across the memory chips to prevent early drive failure. Solid State Systems Sss6698-bb