Hybrid Memory Controller for Unified DRAM and Flash Access

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing computing devices often require costly and risky redesigns to integrate both volatile DRAM and nonvolatile NAND flash memory, as they lack compatible bus interfaces, making it difficult to update existing devices with new memory types without significant hardware changes.

Innovation Solution

A hybrid memory device with a controller that manages both volatile DRAM and nonvolatile flash memory through a single interface, allowing software to access both types of memory via a unified interface, enabling seamless integration and operation without requiring changes to the physical architecture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a device is designed with a single type of memory interface (DRAM or NAND flash), then the device can operate with that memory type, but it cannot support the other memory type without costly and lengthy redesign of the device chipset

Engineering Contradiction:
Improvememory type supportVSAvoidchipset redesign
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates a hybrid memory device that presents a unified DRAM-compatible interface to the host system while internally managing both DRAM and NAND flash memory through a single controller. This allows the device to function as a universal memory solution that supports both volatile and non-volatile memory types without requiring separate interfaces or chipset redesigns.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces a memory controller as an intermediary layer between the host system and the dual memory arrays. This controller translates host DRAM-compatible commands into appropriate operations for either DRAM or NAND flash memory, enabling the host to access both memory types through a single standardized interface without needing to know the underlying memory architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If existing DRAM-based devices are updated to include NAND flash memory, then new features and business models are enabled, but the expense of redesigning the device chipset becomes too costly and risky

Engineering Contradiction:
Improvememory functionalityVSAvoidredesign cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges DRAM and NAND flash memory into a single hybrid memory device that replaces the existing DRAM component. This combination allows the device to provide both volatile and non-volatile storage capabilities while maintaining physical compatibility with existing DRAM slots, eliminating the need for costly chipset redesigns and enabling easy upgrades to existing devices.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a DRAM-compatible interface layer that copies the electrical and protocol characteristics of standard DRAM. This allows the hybrid memory device to present itself as a DRAM component to the host system, enabling drop-in replacement without requiring changes to the host's memory controller or chipset architecture.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If different types of memory are integrated into a single device, then both volatile and nonvolatile storage are available, but the device requires a controller to manage commands and determine which memory type to access

Engineering Contradiction:
Improvedual memory capabilityVSAvoidcontroller logic
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the memory management functions by dedicating specific logic within the controller to handle different memory types. The controller includes separate command interpretation paths and address mapping mechanisms that divide the memory management task into distinct segments for DRAM and NAND flash, allowing efficient handling of both memory types through a unified interface.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2025001B1Hybrid memory device with single interface
Publication Date: 2019.01.23 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP2025001B1 patent drawingFigure 1
  • EP2025001B1 patent drawingFigure 2
  • EP2025001B1 patent drawingFigure 3A

AI summary

Described is a technology by which a memory controller is a component of a hybrid memory device having different types of memory therein (e.g., SDRAM and flash memory), in which the controller operates such that the memory device has only a single memory interface with respect to voltage and access protocols defined for one type of memory. For example, the controller allows a memory device with a standard SDRAM interface to provide access to both SDRAM and non-volatile memory with the non-volatile memory overlaid in one or more designated blocks of the volatile memory address space (or vice-versa). A command protocol maps memory pages to the volatile memory interface address space, for example, permitting a single pin compatible multi-chip package to replace an existing volatile memory device in any computing device that wants to provide non-volatile storage, while only requiring software changes to the device to access the flash.