Slave ID Selection Circuitry for Serial Bus Auto-Configuration

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Solution Overview

Problem

Existing serial communication systems face challenges in uniquely identifying multiple identical slave devices, leading to increased manufacturing costs and complexity, as existing methods require additional pins or infrastructure to provide unique slave IDs.

Innovation Solution

A serial communication device with a memory and slave ID selection circuitry that changes the stored slave ID based on which IO pin is coupled to the supply voltage, allowing multiple identical devices to participate in a serial communication process without using additional IO pins, and optionally using a GPIO pin to select additional unique IDs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional GPIO pins are used to provide unique slave IDs for identical slave devices, then unique identification is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improveunique slave ID identificationVSAvoidadditional GPIO pin and signal routing

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The supply voltage pin (VDD pin) is given a dual function: it serves both as a power supply input and as a slave ID selection input. The slave ID selection circuitry detects which VDD pin receives voltage and uses this information to determine the slave ID, eliminating the need for separate GPIO pins dedicated to ID selection.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The slave device uses its own power supply infrastructure (VDD pins) to automatically determine its slave ID without requiring external control signals or additional configuration pins. The slave ID selection circuitry monitors the power supply status of each VDD pin and autonomously selects the appropriate slave ID based on which pin is powered.

Inventive Principle:

Principle #25Self-service

2Reliability

If eFUSE memory systems are used to provide changeable slave IDs, then unique identification is achieved, but manufacturing cost and design complexity increase

Engineering Contradiction:

Improvechangeable slave IDVSAvoidmanufacturing cost and design complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive eFUSE memory systems with a simple, low-cost slave ID selection circuitry that uses basic electronic components (comparators, logic gates, and multiplexers) to achieve slave ID selection. This circuitry is significantly cheaper to manufacture and easier to implement than eFUSE-based solutions.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If signal timing on serial communication pins is used to determine slave ID, then unique identification is achieved, but the system becomes susceptible to noise

Engineering Contradiction:

Improveunique slave IDVSAvoidnoise susceptibility

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the parameter used for slave ID determination from signal timing (which is susceptible to noise) to power supply voltage presence (which is a stable, noise-immune parameter). The slave ID selection circuitry detects which VDD pin has voltage applied, providing a robust and noise-resistant method for unique identification.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9720872B2Auto-configuration of devices based upon configuration of serial input pins and supply

Publication Date: 2017.08.01 QORVO US INC

AI summary

A device includes a memory, at least two input/output (IO) pins, and slave identifier (ID) selection circuitry. The memory stores a slave ID, which identifies the device to other devices in a serial communication process. The slave ID selection circuitry changes the stored slave ID based on which one of the IO pins is coupled to a supply voltage. By changing the slave ID of the device based on which one of the IO pins is coupled to a supply voltage, a number of devices with otherwise identical slave IDs may change their slave IDs in order to participate in a serial communication process on the same bus. Further, the slave ID of the device may be changed without using an additional IO pin on the device.