MIPI Alliance rolls out sensor interface specification
MIPI Alliance, an international organization that develops interface specifications for mobile and mobile-influenced industries, today introduced a sensor interface specification for mobile, mobile-influenced and embedded-systems applications. The new specification, named MIPI I3C (or MIPI i3c), was developed with the participation of vendors from across the sensor and mobile ecosystems.
The name MIPI SenseWire will be used to describe the application of I3C in mobile devices and the use of the I3C interface for mobile devices connecting to a set of sensors, directly or indirectly.MIPI Alliance issued the announcement in conjunction with MEMS Executive Congress, which is taking place this week in Scottsdale AZ. The new specification, named MIPI I3C (or MIPI i3c), was developed with the participation of vendors from across the sensor and mobile ecosystems. The name MIPI SenseWire will be used to describe the application of I3C in mobile devices and the use of the I3C interface for mobile devices connecting to a set of sensors, directly or indirectly.
“The steadily increasing use of sensors in wireless devices is driving innovation of new and exciting applications for all types of products, yet incorporating numerous sensors in end-user devices is a serious pain point,” said Joel Huloux, chairman of the board of MIPI Alliance. “SenseWire brings a long-awaited, standardized solution to these difficult problems.”
The proliferation of sensors has created significant design challenges to product designers. The challenges are particularly demanding in the handset market, where smartphones often require as many as 10 sensors and more than 20 signals. Yet as these requirements continue to grow, phone architectures can’t scale to deliver the design, cost and performance efficiencies manufacturers need to add more sensors to their products. Further, integration requirements can vary for each sensor, and the digital interfaces available to the market, including I2C and SPI, are numerous. Interface fragmentation increases product development and integration costs. Also, currently available interfaces do not use power efficiently for communication with sensors, and this can limit their potential uses and scalability.
To address these challenges and ensure that the new specification addresses the needs of the broadest possible sensor ecosystem, MIPI Alliance collaborated with MEMS Industry Group (MIG) to survey both groups’ members to assess sensor interface needs and identify technology gaps that existing sensor standards can’t provide. The survey findings helped guide the work of the MIPI Alliance Sensor Working Group, which has led development of the new specification. Companies participating in the MIPI Alliance Sensor Working Group include AMD, Audience, Broadcom, Cadence, Intel Corporation, InvenSense, Lattice Semiconductor, MediaTek, Mentor Graphics, NVIDIA, NXP, STMicroelectronics, Synopsys, Qualcomm Incorporated, QuickLogic, VLSI Plus, Ltd., ZMDI, and others.
“The development of the MIPI I3C specification has been a truly communal development process, with stakeholders from across the industry participating collaboratively in this work,” said Ken Foust, chair of the MIPI Alliance Sensor Working Group. “We set out to develop an interface that is evolutionary, not revolutionary, and that advances I2C and SPI. This new specification will become a superset of both. We fully expect that the interface will have broad market adoption in the mobile ecosystem and beyond.”
In general, SenseWire incorporates and unifies key attributes of I2C and SPI while improving the capabilities and performance of each approach with a comprehensive, scalable interface and architecture. The specification also anticipates sensor interface architectures that mobile, mobile-influenced, and embedded-systems industries will need in the future. The specification should make it easier for system designers to connect and manage sensors in a device, improve time to market for these implementations and enable a greater number of sensors to operate in a device while minimizing power consumption and reducing component and implementation costs. It will also help manufacturers combine multiple sensors from different vendors to enable new features while supporting longer battery life.
The technical features of the MIPI I3C specification include a two-pin interface that is backward compatible with the I2C standard and provides data throughput capabilities comparable to SPI. The technical attributes explain the name for the specification, MIPI I3C, which is derived from its compatibility with I2C.
The new technology can facilitate in-band interrupts within the 2-wire interface, which drastically reduces device pin count and signal paths, and facilitates incorporation of more sensors in a device. On standard CMOS I/O, it supports a minimum data rate of 10 Mbps with options for higher performance high-data-rate (HDR) modes, offering a substantial leap in performance and power efficiency compared to existing options. It also offers multimaster support, dynamic addressing, command-code compatibility and a uniform approach for advanced power management features, such as sleep mode.
“MIG is deeply committed to advancing industry specifications that will ease development of MEMS/sensors-based applications. We were able to support that goal by collaborating with MIPI Alliance members in realizing this important new specification,” said Karen Lightman, executive director of MEMS Industry Group. “The MIPI I3C specification will have a lasting impact. It addresses the need for a standardized interface that ensures low-power operation in microcontrollers — across application, industry and market. Such broad applicability should produce direct benefits to wirelessly connected wearables, toy and gaming devices, healthcare products, and industrial equipment — applications that are the bedrock of the Internet of Things.”
The MIPI I3C specification is scheduled for Working Group completion by year-end 2014, with ratification and approval by the MIPI Alliance Board of Directors and publication in the first quarter of 2015. Companies that have not been involved in the development of the specification but want to participate still have time to join the process, gain early experience with the technology and play a role in the culmination of this work.