Unified Data Bus Inversion Signaling for Power Reduction

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Solution Overview

Problem

Current high-speed memory systems face challenges in efficiently signaling multiple bus states in minimal time using the least number of signaling lines, particularly in reducing adverse effects like cross talk and power consumption, and addressing issues related to data integrity such as poisoning.

Innovation Solution

A unified signaling method and system that utilizes a single indicator line to convey data bus inversion and poisoning status, enabling efficient data masking and inversion techniques to minimize state changes and power consumption, while supporting DBI-DC and DBI-AC modes for masked and unmasked data, and incorporating data poisoning mechanisms to handle uncorrectable errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple separate signaling lines are used for DBI and data masking status indication, then the reliability of data status signaling is improved, but the device complexity and number of signaling lines increases

Engineering Contradiction:
Improvedata status signaling reliabilityVSAvoidnumber of signaling lines
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple status signaling functions (DBI status and data masking status) into a single indicator line. The encoding circuitry uses this single line to convey different status states by utilizing different voltage levels or logic states, thereby reducing the number of signaling lines while maintaining reliable data status indication.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single indicator line serves multiple functions by indicating different data bus statuses (inverted or not inverted, masked or not masked) through different signal states. This multi-functional approach allows the same physical line to convey various types of status information without requiring separate dedicated lines for each status type.

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

2Use of energy by moving object

If data encoding techniques like DBI are used to reduce power consumption and noise, then energy efficiency is improved, but the device complexity increases due to additional encoding circuitry

Engineering Contradiction:
Improvepower consumptionVSAvoidencoding circuitry complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The encoding circuitry performs data bus inversion and status encoding in advance before data transmission. By pre-processing the data and determining the appropriate inversion status and masking status, the system reduces power consumption during actual data transfer operations and minimizes simultaneous switching noise, while the added complexity is confined to the encoding stage.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2791809B1Unified data masking, data poisoning, and data bus inversion signaling
Publication Date: 2017.08.02 ADVANCED MICRO DEVICES INC
  • EP2791809B1 patent drawingFigure 1
  • EP2791809B1 patent drawingFigure 2
  • EP2791809B1 patent drawingFigure 3

AI summary

Provided herein is a method and system for providing and analyzing unified data signaling that includes setting, or analyzing a state of a single indicator signal, generating or analyzing a data pattern of a plurality of data bits, and signal, or determine, based on the state of the single indicator signal and the pattern of the plurality of data bits, that data bus inversion has been applied to the plurality of data bits or that the plurality of data bits is poisoned.