Piscataway, NJ – 9 July 2007 – In response to the increased demand for multimedia functions within mobile terminals and other portable entertainment devices, the Mobile Industry Processor Interface (MIPISM) Alliance today announced the release of the Serial Low-power Inter-chip Media Bus (SLIMbus®) Specification. The SLIMbus standard overcomes limitations of existing digital audio interfaces and reduces the need for outdated control busses, fulfilling the promise of one interconnect standard to replace many.
Motivated by the fragmentation wrought by incompatible proprietary interfaces and redundant outdated standards, the MIPI Alliance brings together more than 120 leading companies in pursuit of open standards to converge interfaces inside mobile terminals. SLIMbus is the latest in a series of MIPI Standards planned by the MIPI Alliance to achieve this goal.
Big Step Forward for Audio and Control Interconnects
SLIMbus delivers significantly more audio capacity than existing I²S and other PCM digital audio busses and an independent messaging channel that offers faster communication than today’s I²C and SPI, yet reduces the number of signals necessary to support these features to just two wires. Offering up to 28Mb/s of scalable bandwidth, SLIMbus™ enables the full flexibility of mixing multiple audio sample rates and control streams to dynamically meet varying system needs.
For instance, one moment a phone user may be listening to high quality 44.1kHz CD-audio, and then receive a call containing 8kHz voice samples. The control signaling for this transition, as well as the simultaneous transfer of the different sample rates, can be handled without dropped samples that can cause clicks or pops. Power conservation is optimized during these constantly changing system states by dynamic “gear-shifting” to match the bus speed with the needed bandwidth.
“Existing standards just didn’t deliver the functionality that new mobile products require, so we developed a standard that could meet those needs,” said Christian Sternell, chair of the MIPI Working Group which developed SLIMbus. “We expect leading phone manufacturers to begin transitioning to SLIMbus as soon as component suppliers deliver products integrating the interface, beginning in 2008.”
At its core, SLIMbus is a multi-drop bus topology using CMOS I/O with framing based upon a Time Division Multiplexed structure. Devices arbitrate for access within the shared message channel, where a Manager allocates channels for guaranteed bandwidth. A Framer device is responsible for sourcing the bus clock along with basic framing information that allow all devices to synchronize and start communication with the Host.
The first implementations of SLIMbus are likely to be seen in audio-centric components within mobile devices, as size, cost and power benefits are most dramatic in these applications.
Broad Industry Support
SLIMbus was developed through the collaborative efforts of leading handset manufacturers, peripheral component manufacturers and microprocessor vendors in the mobile industry.
“More than 15 companies contributed directly to the engineering of this standard, and many more are anxiously planning to implement and use it” said Tom Vial, Chairman of the Board, MIPI Alliance, Inc. “Such broad representation produced a robust technical solution which reflects a healthy diversity of use-cases and emerging system requirements. MIPI is highly optimistic that the industry will rapidly embrace this solution for audio and control interconnects in future mobile systems.”
MIPI Alliance Continues to Deliver Successful Standards
SLIMbus is the latest specification released from MIPI, complementing MIPI’s camera serial interface (CSI-2), physical layer (D-PHY) and display serial interface (DSI) specifications which were released in 2005 and 2006 and are now being implemented in products. Additional standards have been completed for test and debug applications and further work is underway for a variety of new standards including power management, high-bandwidth general purpose interfaces, and software-related interface management challenges.
The Mobile Industry Processor Interface (MIPI) Alliance is an open membership organization that includes leading companies in the mobile industry that share the objective of defining and promoting open specifications for interfaces in mobile terminals. MIPI Specifications establish standards for hardware and software interfaces between the processors and peripherals typically found in mobile terminal systems. By defining such standards and encouraging their adoption throughout the industry value chain, the MIPI Alliance intends to reduce fragmentation and improve interoperability among system components, benefiting the entire mobile industry.
MIPI Specifications are currently available only to MIPI Alliance member companies. Interested companies are welcome to join the MIPI Alliance. Membership includes limited royalty-free intellectual property rights and obligations. For more information on membership in the MIPI Alliance, visit www.mipi.org.
More than 130 member companies participate in the MIPI Alliance, including nearly every leading supplier of mobile phones, applications processors, baseband modems, display panels, camera sensors, and audio and power peripherals. A complete list of member companies can be found at www.mipi.org.
Member testimonials, including quotes from Akustica, Arasan Chip Systems, Inc., Atmel Corporation, austriamicrosystems AG, Broadcom, Freescale Semiconductor, Infineon Technologies AG, LnK, Motorola, National Semiconductor, Nokia Corporation, NXP Semiconductors, Samsung Electronics, Sonion, STMicroelectronics N.V., Texas Instruments Incorporated, Wolfson Microelectronics, and XMOS Semiconductor Ltd., are available at: http://www.mipi.org/sites/default/files/mipi-testimonials-milestones.pdf
MIPI Frequently Asked Questions are available at: http://www.mipi.org/about-mipi/frequently-asked-questions
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Charmain Williams, c/o MIPI Alliance, Inc.
+1 (732) 465-5841