MEMORY UNIT ASSIGNMENT AND SELECTION FOR INTERNAL MEMORY OPERATIONS IN DATA STORAGE SYSTEMS

Disclosed embodiments are directed to systems and methods for assigning and selecting memory units for internal memory operations in data storage systems. The embodiments can improve the efficiency of garbage collection operations by directing dynamic data into memory units with a relatively lower P/E count, directing static and system data into memory units with a relatively higher P/E count, and not mixing static and dynamic data by packing static data into separate memory units from dynamic data. In one embodiment, after completion of garbage collection of blocks, the blocks are each assigned to one of a cool down list and an available memory unit list based on a size limit of the cool down list and a number of program-erase (P/E) operations performed on each block. The blocks are subsequently selected from the lists for write operations according to whether write data includes static or dynamic data.