PCIe TLP Header Fields for Root-Free Endpoint Communication
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Solution Overview
Problem
The complexity of intra-vehicle networks is increased due to the need for multiple transmission interfaces and interface conversions when endpoints in a PCIe system communicate through a root, which is not suitable for high-speed communication scenarios.
Innovation Solution
A PCIe-based data transmission method that allows endpoints to communicate directly without relying on a root by using a TLP with a packet header that includes fields indicating encapsulation information, such as data type and encapsulation parameters, enabling direct communication between endpoints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If endpoints communicate through the root in a PCIe system, then communication between endpoints is enabled, but the complexity of the intra-vehicle network increases due to multiple transmission interfaces and interface conversions
Solution Approach 1:
The patent extracts the root-mediated communication step from the traditional PCIe communication path. By enabling endpoints to communicate directly through the PCIe switch without requiring the root to forward packets, the solution removes the complexity-causing element while preserving communication capability. The TLP packet structure is modified to include direct endpoint addressing information, allowing switches to route packets directly between endpoints.
Solution Approach 2:
The PCIe switch is enhanced to perform multiple functions: it acts as both a traditional forwarding node and a direct communication enabler between endpoints. The switch interprets the extended TLP packet header to determine whether to forward packets through the root or route them directly to the destination endpoint, providing universal communication paths that reduce network complexity.
2Adaptability or versatility
If interface conversion is performed between multiple transmission interfaces, then communication flexibility is improved, but the complexity of the intra-vehicle network greatly increases
Solution Approach 1:
The patent merges multiple transmission interface protocols into a unified PCIe-based communication framework. By standardizing on PCIe TLP packets for all endpoint communications and using the switch to handle protocol translation and routing, the solution reduces the number of interface conversions required while maintaining communication flexibility across different device types.
3Device complexity
If direct communication between endpoints is enabled, then network complexity is reduced, but compatibility with existing PCIe protocols must be maintained
Solution Approach 1:
The TLP packet header is segmented into standard fields and extended fields. The standard fields maintain compatibility with existing PCIe protocols, while the extended fields carry additional information needed for direct endpoint communication. This segmentation allows the protocol to maintain backward compatibility while enabling new communication modes.
Solution Approach 2:
The patent incorporates preliminary compatibility measures by designing the extended TLP header to include fields that can be interpreted by both legacy and enhanced PCIe implementations. Switches and endpoints can choose to ignore or utilize the extended fields based on their capabilities, ensuring smooth integration with existing PCIe infrastructure.
Data Source
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AI summary
This application discloses a PCIe-based data transmission method and apparatus, so that endpoints in a PCIe system can perform communication without using a root (Root), thereby reducing complexity of an intra-vehicle network. The method includes: A first node encapsulates data into a transaction layer packet TLP and then send the TLP to a second node, where the TLP includes a packet header part, a first field and a second field of the packet header part are used to indicate first encapsulation information, and the first encapsulation information includes a data type of the data and at least one encapsulation parameter corresponding to the data type. In embodiments of this application, the first field and the second field are used to indicate the information required for transmitting the data, such as the data type and the encapsulation parameter corresponding to the data type, so that the endpoints can communicate with each other even if the root is not used, thereby reducing complexity of the intra-vehicle network.