Memory system and method of controlling memory system
AssigneeKabushiki Kaisha Toshiba
InventorsHirokuni Yano, Toshikatsu Hida
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Abstract
A forward lookup address translation table and a reverse lookup address translation table stored in a nonvolatile second storing unit are transferred as a master table to a volatile first storing unit at a time of start-up. When an event occurs so that the master table needs to be updated, difference information before and after update of any one of the forward lookup address translation table and the reverse lookup address translation table is recorded in the first storing unit as a log, thereby reducing an amount of the log.
Claims21
A memory system comprising:
- a volatile first storing unit;
- a nonvolatile second storing unit;
- and
- a controller that performs data transfer between a host apparatus and the second storing unit via the first storing unit, wherein
- the second storing unit is capable of storing therein
- a first address translation table for managing forward lookup information that correlates a logical address specified from the host apparatus with a storing position in the second storing unit, and
- a second address translation table for managing reverse lookup information that correlates the storing position in the second storing unit with the logical address, and
- the controller includes
- a table transferring unit that transfers the first address translation table and the second address translation table stored in the second storing unit to the first storing unit as a master table,
- a log control unit that, when an event occurs so that the master table needs to be updated, stores therein difference information before and after update of any one of the first address translation table and the second address translation table as a log in the first storing unit,
- a log reflecting unit that, when a specific first condition is satisfied, stores the log stored in the first storing unit in the second storing unit and reflects the log stored in the first storing unit in the master table stored in the first storing unit, and
- a read/write control unit that controls the data transfer by using the master table and the log stored in the first storing unit.
A method of controlling a memory system that includes a volatile first storing unit and a nonvolatile second storing unit, the method comprising:
- storing a first address translation table for managing forward lookup information that correlates a logical address specified from a host apparatus with a storing position in the second storing unit, in the second storing unit;
- storing a second address translation table for managing reverse lookup information that correlates the storing position in the second storing unit with the logical address, in the second storing unit;
- transferring the first address translation table and the second address translation table to the first storing unit as a master table;
- storing, when an event occurs so that the master table needs to be updated, difference information before and after update of any one of the first address translation table and the second address translation table stored in the first storing unit as a log in the first storing unit;
- and
- storing the log stored in the first storing unit in the second storing unit and reflecting the log stored in the first storing unit in the master table stored the first storing unit, when a specific first condition is satisfied.
Dependencies are inferred from the claim text.