Universal Measurement and Calibration Protocol
The XCP protocol ( XCP ) is a network protocol . It was standardized by ASAM eV in 2003 (ASAM MCD-1 XCP) and is mainly used in automotive electronics development for the coordination (calibration) of parameters and for testing electronic control units . The measurement and calibration protocol enables read and write access to variables or memory contents of microcontroller systems during runtime. Entire data sets can be recorded or stimulated synchronously with events. It also enables programming of the flash memory.
XCP is the successor to the CAN Calibration Protocol (CCP) developed in the mid-1990s . At that time, CAN was the only dominant networking system in automobiles. Over time, other bus systems such as LIN , MOST and FlexRay established themselves , so that an extension of the protocol to other transport media became necessary. XCP also supports synchronous and asynchronous serial interfaces. With Ethernet or USB as the transport medium, XCP also serves as a standardized interface to analog measuring devices and to hardware interface converters to RAM emulators, JTAG or other microcontroller debug interfaces.
As a two-layer protocol, XCP consistently separates the protocol and transport layers from one another and uses a single master / multi-slave concept. XCP always uses the same protocol layer, regardless of the transport layer. As of December 2016, the following ASAM transport layers are defined as standard:
- XCP on CAN
- XCP on CAN FD
- XCP on SxI ( SPI , SCI )
- XCP on Ethernet ( TCP / IP and UDP / IP )
- XCP on USB
- XCP on FlexRay
The measurement and calibration protocols XCP (on CAN as transport layer) and CCP are not compatible with each other. Both aspects, extension and generalization, are expressed by the X in the name XCP (e X tended).
In addition to supporting additional transport layers, many functional improvements were also incorporated into the successor to the CCP protocol:
- Better use of resources in the control unit
- Synchronous data stimulation
- Support of start-up measurements
- Optimized communication through block transfer commands
- Plug & Play configuration
- More precise measurement data acquisition by measuring the time stamp in the control unit (slave)
literature
- Werner Zimmermann, Ralf Schmidgall: Bus systems in vehicle technology - protocols, standards and software architecture . 4th edition. Vieweg + Teubner, 2010, ISBN 978-3-8348-0907-0
- Kai Borgeest: Electronics in vehicle technology - hardware, software, systems and project management . 2nd Edition. 2010, ISBN 978-3-8348-0548-5
- Andreas Patzer, Rainer Zaiser: XCP - The standard protocol for ECU development . 3rd edition, Vector Informatik . Stuttgart 2016
Web links
- official website of ASAM e. V.
- ASAM WIKI Description of the standard in the ASAM WIKI
- ASAM MCD-1 XCP V1.5.0 Description of the V1.5.0 standard on the ASAM website
Individual evidence
- ↑ Description of the standard on the ASAM website
- ↑ Andreas Patzer, Rainer Zaiser: XCP - The standard protocol for ECU development . Vector Informatik, Stuttgart 2016.