Radian Memory Systems, Inc.

Alan Chen

Andrey V Kuzmin

Robert Lercari

Craig Robertson

Mike Jadon

This disclosure provides techniques for managing memory which match per-data metrics to those of other data or to memory destination. In one embodiment, wear data is tracked for at least one tier of nonvolatile memory (e.g., flash memory) and a measure of data persistence (e.g., age, write frequency, etc.) is generated or tracked for each data item. Memory wear management based on these individually-generated or tracked metrics is enhanced by storing or migrating data in a manner where persistent data is stored in relatively worn memory locations (e.g., relatively more-worn flash memory) while temporary data is stored in memory that is less worn or is less susceptible to wear. Other data placement or migration techniques are also disclosed.

Management of discrete namespaces by nonvolatile memory controller

This disclosure provides techniques hierarchical address virtualization within a memory controller and configurable block device allocation. By performing address translation only at select hierarchical levels, a memory controller can be designed to have predictable I/O latency, with brief or otherwise negligible logical-to-physical address translation time. In one embodiment, address transition may be implemented entirely with logical gates and look-up tables of a memory controller integrated circuit, without requiring processor cycles. The disclosed virtualization scheme also provides for flexibility in customizing the configuration of virtual storage devices, to present nearly any desired configuration to a host or client.

Hierarchical storage device with host controlled subdivisions

A host stores 'context' metadata for logical block addresses (LBAs) in a manner tied to physical location. Notwithstanding log-structured or copy on write processes, the host is then provided with immediate context when the host is called upon to assist a memory controller with data identified by physical location, for example, for memory reconfiguration, garbage collection, wear leveling or other processes. The metadata for example can provide the host with insight as to which data may be moved to enhance performance optimization and where that data can be placed. In one embodiment, the host writes back one or more references that span multiple layers of indirection in concert with write of the underlying data; in another embodiment, the context can point to other metadata.

Techniques for directed data migration

Memory management of nonvolatile discrete namespaces

Nonvolatile memory controller supporting variable configurability and forward compatibility

Storage deveice that garbage collects specific areas based on a host specified context

Cooperative flash management of storage device subdivisions

Storage device with division based addressing to support host memory array discovery

Storage drive with NAND maintenance on basis of segments corresponding to logical erase units

Storage drive with defect management on basis of segments corresponding to logical erase units

Storage system with division based addressing and query based cooperative flash management

Storage system with division based addressing and cooperative flash management

Growing community of inventors

Simi Valley, CA, United States of America

Alan Chen