ISO 20794-4:2020 (R2025)

This document specifies the CXPI data link layer and the CXPI physical layer. The DLL is based on: — priority-based CXPI network access; — non-destructive content-based arbitration; — broadcast frame transfer and acceptance filtering; and — node related error detection and error signalling. The CXPI physical layer (PHY) requirements comprise of: — physical signalling (PS) sub-layer, which specifies the requirements of the clock generation function, the encoding and decoding of CXPI frames, and bit-wise collision resolution logic; — physical media attachment (PMA) sub-layer, which specifies the requirements of the signal shaping waveform logic; — physical media dependent (PMD) sub-layer, which specifies the requirements of the CXPI network termination, electrostatic discharge protection, etc., and device connector requirements; and — physical media (PM), which specifies the requirements of the CXPI network cable/wiring harness.