A method of prioritizing program and erase commands received in an operation queue for a memory includes the step of storing a placeholder erase command in the operation queue. Subsequent erase commands are absorbed by 1) storing the subsequent erase command in the operation queue; 2)...http://www.google.de/patents/US5809541?utm_source=gb-gplus-sharePatent US5809541 - Methods for prioritizing erase and program commands in a nonvolatile semiconductor memory device 
