US 5,535,399 A · Solid state disk drive unit having on-board backup non-volatile memory

Abstract

Disclosed is a solid state disk drive, including a volatile, electronic RAM, memory and a non volatile, magnetic disk. The drive continuously saves unique data stored in the memory back to the disk. Additionally, the drive includes a number of tables and bit fields, in both volatile electronic memory and disk, for generally keeping track of what data has been restored from disk to memory, what data in the memory has been modified since it was restored from disk, and what modified data in the memory has been saved back to disk. In the event of a primary power outage, the drive first saves the volatile tables onto disk, and then saves the volatile, modified data onto disk, while using auxiliary power. If, however, auxiliary power is lost before any or all of the modified data is saved on disk, the saved tables provide information which enables the drive to distinguish the valid from the invalid data on disk.

Claims27

Dependent claims

A self contained, solid state disk drive data storage apparatus for storing and retrieving blocks of user data received from a host computer via an external bus and comprising:

a non-volatile memory comprising at least one disk drive for storing data blocks by logical block addresses and having a predetermined data storage capacity of at least 100 megabytes of user data;
volatile memory means for storing data blocks by logical block addresses transferred from corresponding logical block addresses of said non-volatile memory and having a predetermined data storage capacity approximately equal to the capacity of the non-volatile memory;
a processing means for transferring data between said non-volatile memory means and said volatile memory means via an internal bus structure, and
first status means within said volatile memory means for indicating that data stored in said volatile memory means has been modified by said host computer after said data stored in said volatile memory was transferred from said non-volatile memory.

1 more element

A self-contained, solid state disk data storage apparatus for storing data block received from a host computer comprising:

an electromechanical recording and playback device having a multiplicity of logical block addresses, there being a logical block address at which each data block is stored;
a dynamic random access memory array having an access time to a data block shorter than an access time of the electromechanical recording and playback device and having a multiplicity of logical block addresses, there being a logical block address at which each data block is stored, logical block addresses of the dynamic random access memory array for a particular data block corresponding to logical block addresses for the particular data block stored within the electromechanical recording and playback device;
a memory including a data structure table having a logical block address which corresponds to the logical block addresses of said electromechanical recording and playback device and the dynamic random access memory array for each data block, the table for storing data which indicates that data stored in said dynamic random access memory array has been modified after it was transferred from said electromechanical recording and playback device;
and
processing means for scanning said data structure table to determine if any of the data blocks in said dynamic random access memory array has been modified by the host computer, and for saving a copy of modified data blocks in said electromechanical recording and playback device while said apparatus is in a WRITE ENABLE mode.

2 more elements

Dependencies are inferred from the claim text.

Solid state disk drive unit having on-board backup non-volatile memory

Life of this patent

Solid state disk drive unit having on-board backup non-volatile memory

Life of this patent

Abstract

Claims27