A re-programmable non-volatile memory system, such as a flash EEPROM system, having its memory cells grouped into blocks of cells that are simultaneously erasable is operated to perform memory system housekeeping operations in the foreground during execution of a host command, wherein the housekeeping...http://www.google.com.hk/patents/US7315917?utm_source=gb-gplus-share專利 US7315917 - Scheduling of housekeeping operations in flash memory systems
