I/O Card Architecture for Extensible Storage Backplane

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Solution Overview

Problem

Network attached storage (NAS) devices face complexity and cost challenges due to limited I2C addressing capabilities and the need for different hardware and software configurations as the number of drives increases, requiring more powerful processors and modified software for each configuration.

Innovation Solution

An extensible I/O card with a serial addressing scheme and shift registers allows for a common architecture to manage multiple ranges of storage devices, enabling auto-detection and configuration of drives, power management, and RAID control without requiring separate software development for each configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If I2C port expanders are used to detect/control drives, then a fixed number of drives can be managed, but the addressing space is limited and cannot control a large number of drives

Engineering Contradiction:
Improvenumber of drivesVSAvoidI2C addressing complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The I/O card is divided into multiple modular I/O modules (SAS/SATA modules, optical modules, etc.), each with its own controller. This segmentation allows each module to be independently addressed and controlled, enabling expansion beyond limited I2C addressing space while maintaining manageable complexity through modular architecture

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from flat I2C addressing to a hierarchical addressing scheme where the I/O card controller provides a root I/O address, and individual I/O modules provide subordinate I/O addresses. This dimensional change in addressing structure enables control of many more devices by organizing addresses in tiers rather than a single flat namespace

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If different hardware configurations are used to support different numbers of drives, then each configuration can be optimized, but hardware and software development becomes difficult to manage and costs increase

Engineering Contradiction:
Improvedrive configuration flexibilityVSAvoidhardware and software design complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

A single I/O card design supports multiple drive configurations (4, 8, 16, 32 drives) through modular I/O modules that can be configured in different quantities. The common I/O card controller and standardized interface architecture provide universal functionality across all configurations, eliminating the need for different hardware designs for different drive counts

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

Solution Approach 2:

The system dynamically adapts to different configurations through hot-pluggable I/O modules and runtime detection capabilities. The I/O card controller can detect which modules are present and configure resource allocation dynamically, allowing the same hardware platform to serve multiple configurations without requiring pre-configured hardware variants

Inventive Principle:
Principle #15Dynamics

3Quantity of substance

If more powerful processors are used to support increased number of drives, then drive management capability improves, but cost increases

Engineering Contradiction:
Improvenumber of drivesVSAvoidprocessor power requirement
Core Design Contradiction:
Quantity of substanceVSPower

Solution Approach 1:

Processing responsibilities are segmented and distributed across multiple I/O module controllers rather than concentrated in a single powerful processor. Each I/O module has its own controller that handles local drive management tasks, reducing the processing burden on the main system processor and enabling scalable drive support without proportionally increasing processor requirements

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3786805B1I/O card architecture based on a common controller
Publication Date: 2022.06.29 WESTERN DIGITAL TECHNOLOGIES INC
  • EP3786805B1 patent drawingFigure 1
  • EP3786805B1 patent drawingFigure 2
  • EP3786805B1 patent drawingFigure 3

AI summary

The embodiments provide a backplane for a storage device that is readily extensible to accommodate a range storage media. In some embodiments, the controller is provided on a motherboard. In order to support a different numbers of bays, various management riser cards are provided on the motherboard to expand the capacity of the backplane while still using the same controller. The backplane supports a serial addressing scheme and shift registers to identify ports connected to the storage device controller to allow for different numbers of storage media to be connected to the motherboard. This allows the storage device controller to use the same addressing protocol and software for any number of drive bays.