BACKGROUND OF THE INVENTION

Field of the Invention

The disclosure relates generally to a flash memory device and a prefetch method thereof.

Description of the Related Art

When a system is powered ON, the solid-state disk is usually powered ON as well. However, the period between when the solid-state disk is powered ON and when the solid-state disk is first accessed is idle time. In order to effectively improve the performance of the solid-state disk, it is necessary to utilize this idle time more effectively for improving the access speed of the solid-state disk.

BRIEF SUMMARY OF THE INVENTION

In an embodiment, a storage device comprises a flash memory array and a controller. The flash memory array stores a plurality of user data. After the controller finishes initialization, the controller accesses the user data in the flash memory array according to a plurality of host commands and an H2F mapping table and records a plurality of address information about the user data in a powered-ON access table.

According to an embodiment of the invention, the size of the powered-ON access table is less than the H2F mapping table.

According to an embodiment of the invention, the address information is a plurality of logic addresses of the user data.

According to an embodiment of the invention, the address information further comprises a plurality of physical addresses of the user data.

According to an embodiment of the invention, the controller records, according to an access order of the user data, the address information in the powered-ON access table.

In another embodiment, a storage device comprises: a flash memory array and a controller. The flash memory array stores a plurality of user data. After the controller finishes initialization, the controller determines whether a powered-ON access table exists in the flash memory array. When the powered-ON access table exists in the flash memory array, the controller prefetches the user data corresponding to the powered-ON access table to a data register.

According to an embodiment of the invention, the controller further prefetches the user data corresponding to the powered-ON access table to the data register according to an H2F mapping table.

According to an embodiment of the invention, when the user data corresponding to the powered-ON access table exceeds the capacity of the data register, the controller only prefetches a part of the user data corresponding to the powered-ON access table to the data register.

According to an embodiment of the invention, the controller sequentially prefetches the user data corresponding to the powered-ON access table to the data register.

According to an embodiment of the invention, after the controller finishes the initialization and before the controller receives a host command, the controller prefetches the user data corresponding to the powered-ON access table to the data register.

In yet another embodiment, a method for building a powered-ON access table of a storage device comprises: executing an initialization; accessing a plurality of user data stored in a flash memory array according to a plurality of host commands and an H2F mapping table; and recording address information of the user data in the powered-ON access table.

In yet another embodiment, a method for utilizing a powered-ON access table of a storage device, comprises: executing an initialization; and determining whether the powered-ON access table exists. When the powered-ON access table exists, prefetching user data corresponding to the powered-ON access table from a flash memory array to a data register.

According to an embodiment of the invention, the method further comprises: accessing the storage device according to a plurality of host commands, the powered-ON access table, and an H2F mapping table.

According to an embodiment of the invention, the method further comprises: when the powered-ON access table does not exist, accessing the storage device according to a plurality of host commands and an H2F mapping table.

A detailed description is given in the following embodiments with reference to the accompanying drawings.

