Self-Synchronizing SPI Interface Hardware Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing Serial Protocol Interface (SPI) communication methods face limitations in achieving high communication speeds due to specific on-chip implementations and electrical characteristics of board interconnections, leading to timing violations and requiring complex software procedures for synchronization.

Innovation Solution

A self-synchronization mechanism is introduced, which includes a self-synchronizer module that performs initialization in hardware, allowing for peak-speed communication without software intervention and is insensitive to delays in the SPI clock path, enabling automatic selection of full-speed operation after initialization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If software-driven synchronization procedures are used to handle timing violations, then communication reliability is improved, but communication speed is reduced and device complexity increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidcommunication speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system performs self-synchronization automatically through hardware detection of the MISO signal transition. The synchronizer module detects the first transition on the MISO line and autonomously adjusts the sampling clock phase, eliminating the need for external software intervention or handshaking protocols. This self-service mechanism maintains reliability while enabling peak-speed communication.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces software-driven synchronization procedures with a hardware-based self-synchronization mechanism. The synchronizer module uses electrical signal detection and automatic phase adjustment circuitry to replace what would traditionally require software timing management, thereby improving both speed and reducing CPU overhead.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If hardware-based self-synchronization is implemented, then communication speed is improved and software complexity is reduced, but device complexity increases

Engineering Contradiction:
Improvecommunication speedVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The synchronizer module serves multiple functions: it detects MISO signal transitions, generates synchronization commands, adjusts the sampling clock phase, and maintains peak-speed operation. By consolidating these functions into a single hardware module, the patent avoids the complexity of separate software routines and multiple control circuits.

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

Solution Approach 2:

The system dynamically changes the phase parameter of the sampling clock based on detected MISO transitions. The synchronizer module adjusts the clock phase in real-time to optimize sampling timing, enabling peak-speed communication without requiring complex protocol management or multiple clock domains.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If peak-speed communication is enabled without initialization, then communication speed is maximized, but timing violations occur due to delays in SPI clock path

Engineering Contradiction:
Improvecommunication speedVSAvoidtiming accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The synchronizer module performs preliminary detection of the MISO signal transition before full-speed communication begins. By detecting the first transition and adjusting the sampling clock phase in advance, the system ensures that subsequent peak-speed operations will be properly synchronized, preventing timing violations while maintaining maximum communication speed.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3098720B1A self-synchronizing interface, corresponding device and method
Publication Date: 2018.07.04 STMICROELECTRONICS SRL
  • EP3098720B1 patent drawingFigure 1~3
  • EP3098720B1 patent drawingFigure 4~6
  • EP3098720B1 patent drawingFigure 7~8

AI summary

A serial protocol interface in a communication device (MD) exchanging data (MOSI, MISO) over a communication link (121, 122, 123) is operated by: - sending output data (MOSI) on (122) the communication link, and - receiving input data (MISO) on (121) the communication link, these input data (MISO) being synchronous with a clock signal (SCK, SCLK) generated at the communication device (MD) and propagated (123) over the communication link (121, 122, 123), - initializing operation by exchanging data over the communication link (121, 122, 123) by sending output data (MOSI) on the communication link (122) at a first data rate, - detecting a signal transition in the input data (MISO) received on the communication link (121), and - once such a transition is detected, exchanging data over the communication link (121, 122, 123) at a second data rate, higher than the first data, with the exchanging of data at a second data rate synchronized (18) as a function of said signal transition.