Methods for writing data to non-volatile memory-based mass storage devices
Methods of operating a non-volatile solid state memory-based mass storage device having at least one non-volatile memory component. In one aspect of the invention, the one or more memory components define a memory space partitioned into user memory and over-provisioning pools based on a P/E cycle count stored in a block information record. The storage device transfers the P/E cycle count of erased blocks to a host and the host stores the P/E cycle count in a content addressable memory. During a host write to the storage device, the host issues a low P/E cycle count number as a primary address to the content addressable memory, which returns available block addresses of blocks within the over-provisioning pool as a first dimension in a multidimensional address space. Changed files are preferably updated in append mode and the previous version can be maintained for version control.
1. In a computer system comprising a host, a method of storing data in a non-volatile solid state memory-based mass storage device, the mass storage device having a substrate and at least one non-volatile memory component mounted thereon, memory locations in the non-volatile memory component having first order addresses and second order addresses, the method comprising:
generating with the non-volatile memory component a record of the number of programming cycles relating to the first order address;
transmitting the record to the host;
selecting with the host a low number of programming cycles within a range of numbers of programming cycles of records relating to the first order addresses as an initial address for a write access to the non-volatile memory device.
2. The method of claim 1 , wherein the non-volatile memory components are NAND flash memory components and the first order addresses correspond to block addresses.
3. The method of claim 1 , wherein the host issues a low number of the range of numbers of programming cycles to a content addressable memory and the content addressable memory returns the addresses of available blocks.
4. The method of claim 3 , wherein the memory locations corresponding to the first order addresses in the non-volatile memory device comprise a user memory space and an over-provisioning memory space.
5. The method of claim 4 , wherein the number of programming cycles of the first order addresses only from blocks assigned to the over-provisioning pool is transmitted to the host.
6. The method of claim 5 wherein, after a block is completely written, it is moved into the user memory space.