Bus Bit Inversion Using Hamming Distance to Cut Wire Count

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Solution Overview

Problem

High-speed and high-bandwidth data transmission across a bus requires numerous communication channels, leading to increased power consumption and area overhead, which is undesirable for mobile or wireless devices where battery life and device size are critical.

Innovation Solution

A method that calculates a parity check code and Hamming distance for data codes, inverting them if the distance is greater than half the number of bits, and sends the inverted codes over the bus without additional signal lines, reducing the need for extra wires and minimizing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If more communication channels are used to achieve high-speed and high-bandwidth data transmission, then data transmission capability is improved, but power consumption increases

Engineering Contradiction:

Improvedata transmission capabilityVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies bus inversion by inverting the data code when the number of transitions exceeds a threshold. This reduces the number of signal transitions during data transmission, thereby lowering power consumption while maintaining high-bandwidth communication capability through the same physical bus

Inventive Principle:

Principle #13The other way round (Inversion)

2Productivity

If more communication channels are used to achieve high-speed and high-bandwidth data transmission, then data transmission capability is improved, but area overhead increases

Engineering Contradiction:

Improvedata transmission capabilityVSAvoidarea overhead

Core Design Contradiction:

ProductivityVSArea of stationary object

Solution Approach 1:

The patent merges the data code and inversion control information into a single bus transmission channel. By encoding the inversion control within the data code itself (using the most significant bit), the system eliminates the need for separate control wires, reducing area overhead while maintaining high transmission capability

Inventive Principle:

Principle #5Merging (Combining)

3Use of energy by moving object

If additional inversion signal lines are used to control bus inversion, then power consumption is reduced, but wire count increases

Engineering Contradiction:

Improvepower consumptionVSAvoidwire count

Core Design Contradiction:

Use of energy by moving objectVSQuantity of substance

Solution Approach 1:

The patent makes the bus lines multi-functional by using them for both data transmission and inversion control. The most significant bit of the data code serves dual purposes: as part of the data payload and as the inversion control signal, eliminating the need for dedicated control wires

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11139830B2Bit inversion for data transmission

Publication Date: 2021.10.05 QUALCOMM INC

AI summary

In certain aspects, a method for sending data over a bus comprises: calculating a parity check code for a new data code, wherein the new data code comprises a number of bits in the new data code; calculating a Hamming distance between the new data code and a prior data code; and if the Hamming distance is greater than half of the number of bits in the new data code: inverting the new data code and the parity check code to obtain an inverted new data code and an inverted parity check code; and sending the inverted new data code and the inverted parity check code to the bus.