1. A method of reading data from a memory ( 102 ) and writing data to a memory ( 102 ) by a host ( 100 ), in which an available time for performing a processing assignment is limited by the host ( 100 ), characterized in that the available time is the sum of a first time unit ( 351 ) planned for processing the assignment, and a second time unit ( 358 ) made available for recovering processing errors, the second time unit ( 358 ) being available for a group of processing assignments ( 351 to 357 ) comprising said processing assignment.