Case Study ROHM Develops Additional Product Families to Promote CXPI Leveraging Keysight’s CXPI Bus Analyzer for Design Evaluation

ROHM Develops Additional Product Families to Promote CXPI Leveraging Keysight’s CXPI Bus Analyzer for Design Evaluation

LIN is more widely used in automobile bodies to control side mirrors, electric seats, door locks, etc. because it is less expensive and fast enough for such applications, which do not require such high reliability and quick responses as CAN can offer. On the contrary, point-to-point communication through wire harnesses is still used for HMIs (human-machine interfaces) to control windshield wipers, lights, and steering wheel switches, which need instant responses, because LIN is too poor in its response time and reliability to realize multiplex communication.

The Society of Automotive Engineers of Japan, Inc. (JSAE) established the CXPI (Clock Extension Peripheral Interface) standard to solve LIN’s issues. The JSAE aims to make CXPI an international standard by having it reviewed by the SAE (Society of Automotive Engineers) and ISO (International Organization for Standardization). The standard improves response time and reliability to allow multiplex communication with HMIs, aiming to further reduce automobile weight by reducing the weight of wire harnesses, and consequently lowering fuel consumption.

In September 2015, ROHM Co., Ltd. (ROHM) announced the industry’s first CXPI transceiver IC, the BD41000FJ-C (Figure 1). ROHM has been proactively developing derived products by taking advantage of the launch of its transceiver ICs ahead of those of its competitors. Keysight’s CXPI bus analyzer played an active role in supporting ROHM in its design evaluations.

We interviewed ROHM representatives on their efforts made to popularize CXPI and the benefits of using CXPI bus analyzers.

The goal is to “promptly launch the product families that will propel the popularization of the CXPI standard”

Today, a Tier 1 company needs to procure necessary components such as transceivers, microcontrollers, and power circuits individually and design ECUs on its own when adopting CXPI, which cost more to design and might create psychological barriers.

ROHM has already commercialized transceiver ICs, which is one of ROHM’s advantages. ROHM aims to make it easy for Tier 1 companies to develop products, and contribute to the market’s adoption of CXPI by promptly launching products that have built-in components such as microcontrollers, power supply circuits, intelligent power devices (IPDs), and motor drivers.

For example, CXPI communication involves a master and slave, each of which comprises a transceiver, microcontroller, and other necessary components. According to the basic concepts of CXPI, CXPI may not need a microcontroller if the slave has the transceiver handle some key communication processes.

Removing microcontrollers from slaves can reduce the number of components in a module, which should lower the hurdle for Tier 1 companies and other companies to adopt CXPI.