CXPI is an in-vehicle communication protocol standard originating in Japan, established to reduce wire harnessing (and consequently, vehicle weight) and enable multiplexing between point-to-point connected devices.

【Key Features of CXPI】 

• Two access methods: event-triggered and polling
  ・The event-triggered method employs CSMA/CR (Carrier Sense Multiple Access with Collision Resolution), a non-destructive arbitration method similar to CAN.
  ・The polling method, similar to LIN, requires the slave node associated with the ID (and requested by the master) to transmit the corresponding data. 
  

• CXPI communication can be achieved using UART without requiring a dedicated communication controller.

• Utilizes PWM as the modulation scheme.
  ・Enables bit-by-bit synchronization. 
  ・The master node provides a clock to the communication bus, and slave nodes use this clock for communication.。
  

• Adopts a single-wire bus system.
  Data containing clock signals is transmitted and received over a single-wire communication bus, supporting communication speeds of up to 20 kbps.
  

• Supports transmission and reception of frames longer than the 8-byte limit of Classic CAN and LIN
   (Communication bandwidth is easily maintained even when adding message verification data.) 
  Data can be transmitted in frames, typically 12 bytes per frame, up to 255 bytes for burst frames.
  

• Employs CRC for error detection.
  The use of CRC ensures communication reliability.
  

【Protocol Comparison for Communication Requirements in the HMI Domain】

AUBIST CXPI is a Functional Cluster (FC) that provides CXPI communication services within the "AUBIST" family of AUTOSAR-compliant in-vehicle platform software.

【Objectives / Advantages】

• A communication protocol developed by DENSO Corporation.
  Proven track record of adoption in mass-produced Toyota vehicles.
• A low-cost in-vehicle LAN protocol.
  Ideal for multiplexing hardwired connections or as a replacement for LIN. 
• Intended for use as a sub-bus for advanced in-vehicle LANs such as CAN. 
  Applications include combination switches, door switches, seat controls, rain sensors, wiper controls, mirror controls, air conditioning switches, etc. 

【AUBIST CXPI Development Concepts】

•  Integrated within AUBIST without impacting other functions 
  ・Interfaces with related modules as an AUTOSAR CDD (Complex Driver) 
  ・Configurable via AUBIST tools 
  
  
•  Designed for package optimization: 
  ・Supports resource-efficient configurations capable of operating without a standard COM (Communication) module. 
  ・Provides CXPI stack not present in AUTOSAR CP architecture as a single package including dedicated CXPI COM, MCAL, and transceiver drivers. 
  ・Compliant with target OEM-specific requirements. 
  ・Supports functional safety standards. 
  
  

【AUBIST CXPI Functional Overview (Basic Functions)】

【AUBIST CXPI Case Study Material】 
 The following downloadable material showcases AUBIST CXPI use cases, examples of evaluation/verification environment setup, and microcontroller implementation results. It can be accessed free of charge. 

For customers placing orders by Thursday, April 30, 2026, we are offering evaluation licenses for AUBIST CXPI at half price.
This is an excellent opportunity for customers considering CXPI-compatible development. Please contact us for more info. 

【Campaign Details】

• The half-price promotional discount applies to orders placed no later than Thursday, April 30, 2026. 
  
  
• Please note specific pricing for the evaluation license and other details will only be provided to those who submit the inquiry form.
  
  
•  Even if you are still in the process of evaluating and you are not yet ready to commit yet, or you simply want to know the price, we invite you to submit the inquiry form. 
  
  
• Submitting an inquiry form does not commit you to purchasing the evaluation license.