Persistent Write Tracking in Non-Volatile Memory Systems

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional non-volatile memory systems face challenges in achieving high performance and efficiency for persistent write operations across different data sizes, with existing solutions either relying on costly energy storage devices or incurring significant performance costs due to flushing all previous write operations to persistent memory.

Innovation Solution

A memory system that performs persistent writes to non-volatile memory upon receiving a Persistent Write command, providing a write identification and completion indication, and supports various granularities through dedicated signaling and energy-backed or non-energy-backed configurations, allowing for efficient and high-performance operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all previous write operations are flushed to persistent memory while waiting for completion status, then data persistence is ensured, but performance deteriorates significantly due to blocking concurrent operations

Engineering Contradiction:
Improvedata persistenceVSAvoidwrite operation performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent segments write operations into individual tracked units using write identification values (WIDs). Instead of flushing all writes collectively, the system can track and confirm individual write completions independently, allowing selective acknowledgment of persistent writes without blocking other operations. This segmentation enables fine-grained control over persistence confirmation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary tracking mechanism that records write completion status without requiring actual data flushing. The WID acts as an intermediary identifier that allows the system to confirm write persistence to the application layer without physically flushing all data to persistent memory, thereby decoupling the persistence confirmation from the actual flush operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If energy storage devices such as super-capacitors or batteries are used to back energy for flushing intermediate buffers, then persistence during power failure is achieved, but device complexity and cost increase

Engineering Contradiction:
Improvepersistence during power failureVSAvoidenergy storage device requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent enables the memory system to self-manage write tracking and persistence confirmation without requiring external energy storage devices. The WID-based tracking mechanism allows the system to autonomously monitor write completion status and provide persistence confirmation based on tracked state rather than physical flush operations, eliminating the need for super-capacitors or batteries.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent creates a logical copy or representation of write completion status through WID tracking. Instead of requiring physical persistence of all data in intermediate buffers, the system maintains a tracked representation of write completion that can be confirmed to applications without actually flushing all data, thereby reducing reliance on energy-backed buffering infrastructure.

Inventive Principle:
Principle #26Copying

3Reliability

If explicit confirmation of write operations to persistent memory is provided, then persistence expectation is satisfied, but operation overhead increases compared to volatile memory writes

Engineering Contradiction:
Improvewrite persistence confirmationVSAvoidprotocol overhead
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary tracking of write operations using WIDs before persistence confirmation is needed. By pre-establishing the tracking mechanism and assigning identifiers to write operations, the system prepares the infrastructure for persistence confirmation in advance, reducing the overhead during actual write operations. The tracking state is maintained ready for confirmation without requiring additional processing at write time.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3682331B1Persistent writes for non-volatile memory
Publication Date: 2023.12.27 QUALCOMM INC
  • EP3682331B1 patent drawingFigure 1
  • EP3682331B1 patent drawingFigure 2A
  • EP3682331B1 patent drawingFigure 2B

AI summary

Systems and methods for persistent operations include a host and a memory system. The memory system, upon receiving a Persistent Write command and associated write data from the host, performs a Persistent Write of the write data to a non-volatile memory in the memory system based on the Persistent Write command. The memory system may also a receive a write identification (WID) associated with the Persistent Write command from the host and provide, upon successful completion of the Persistent Write, a Persistent Write completion indication along with the associated WID to the host.