A new standard has been released for computer-on-modules which aims to standardize the footprint and interface set of low-power and ultra-low-power...
A new standard has been released for computer-on-modules (COM) which aims to standardize the footprint and interface set of low-power and ultra-low-power application processors based on MCU32, ARM and x86 architectures across different sockets, manufacturers and architectures.
Release 1.0 of the OSM computer-on-module specification, where OSM stands for open standard module, defines one of the first standards for directly solderable and scalable embedded computer modules. It also marks a milestone in the miniaturization of modular COM/carrier designs, replacing credit card-sized modules with postage stamp-sized ones with a maximum 45mmx45mm footprint.
The specification is defined by SGET (Standardization Group for Embedded Technologies), a not-for-profit association headquartered in Munich, Germany. Target applications of the new module standard include internet of things (IoT) connected embedded and edge systems that run open-source operating systems and are used in harsh industrial environments.
“OSM modules give ODMs and OEMs an ultra-miniature form factor with attractive pricing and high scalability. Since the modules are application-ready and come with all necessary software drivers and BSPs, and since the specification is open source – both in terms of the hardware and software – we expect them to be of high interest for the globally active embedded and IoT system development community,” said Martin Unverdorben, chairman of the SGET STD.05 standard development team, which started work in October 2019.
Similar to computer-on-module standards and products, OSM modules simplify and accelerate the design-in of processors. At the same time, applications become processor-agnostic, which makes them scalable and future-proof. According to SGET, they also protect NRE investments and extend long-term availability, ultimately increasing the return on investment and sustainability of embedded systems. Next to these advantages – which OSM modules have in common with all earlier computer-on-module specifications – the OSM specification offers an extra level of ruggedness as a result of its BGA design and automated surface mount technology (SMT), which can further reduce production costs in series production.
All OSM modules are also published and licensed under Creative Commons Plus (CC+) dual license. This allows an open licensing model, such as the Creative Commons Attribution-ShareAlike license (CC B-SA 4.0) for a defined set of materials, components and software, and a commercial license for everything not included in this set. This ensures that development data, such as block diagrams, libraries and BOMs resulting from the development of OSM modules, will be publicly available. Yet it is still possible to license the intellectual properties (IP) of a carrier board design commercially without violating the open-source idea.
The new OSM specification expands the portfolio of SGET module specifications with solderable BGA mini modules that are significantly smaller than previously available modules. The largest OSM module, measuring 45x45mm, is 28% smaller than the µQseven (40x70mm), a standard also hosted by SGET, and 51% smaller than SMARC (82x50mm).
Other module sizes in the new OSM specification are smaller. OSM Size-0 (zero) has the smallest footprint with 188 BGA pins on 30x15mm. OSM Size-S (small) measures 30x30mm with 332 pins, OSM Size-M (Medium) offers 476 pins on 30x45mm, and Size-L (large) – as mentioned earlier – measures 45x45mm with 662 BGA pins. SMARC, by comparison, specifies 314 pins and Qseven 230. This means that BGA design makes it possible to implement significantly more interfaces on a smaller footprint – which is groundbreaking, both in terms of miniaturization and the increasing complexity of requirements.
What feature sets are available in the various size configurations?
The interfaces vary in type and design depending on the size of the OSM modules. In maximum configurations, OSM modules provide all functions that make up an open programmable embedded, IoT or edge system, including GUI.
Modules from Size-S upwards offer video interfaces for up to 1x RGB and 4-channel DSI. Size-M modules can additionally support 2x eDP/eDP++, and Size-L adds 1x LVDS interface for graphics. Hence maximum configurations can provide up to 5 video outputs in parallel. All modules from Size-S upwards further offer a 4-channel camera serial interface (CSI). Size-L modules provide up to 10 PCIe lanes for quick connection of peripherals; Size-M offers 2x PCIe x1, and Size-S 1x PCIe x1. In view of their extremely miniaturized footprint, Size-0 modules do not feature any of the I/Os mentioned but do offer all the interfaces listed in the OSM specification, which provisions up to 5x Ethernet for system-to-system communication.
In addition, all modules have what is called a communication area, providing 18 pins for antenna signals for wireless communication or the integration of field buses. Next, there are up to 4x USB 2.0 or 2x USB 3.0 (only in Size-L), up to 2x CAN, and 4x UART. Flash storage media can be connected via UFS. Up to 19 pins are further available for manufacturer-specific signals.
Finally, and to complete the feature set, there are up to 39 GPIOs, SPI, I2C, I2S, SDIO and 2x analog inputs. As a safeguard for the future and to ensure that any future expansions are backward compatible, up to 58 pins are reserved for future purposes.