Adlink has demonstrated its support for the ISM and SUMIT standards with the CoreModule range of embedded PC/104 SBCs (single board computers).ISM, short for industry standard module, is a pure 90 x 96 mm form factor (compatible with PC/104) that addresses shortcomings of existing small form factors, such as:
* Fitting circuitry without extending beyond the board outline.
* Meeting top- and bottom-side component height restrictions.
* Decoupling form factors from expansion interfaces.
* Enabling flexible expansion bus and I/O connectorisation.
* Allowing bus combinations that were previously undefined and unnamed.
SBC manufacturers have struggled to fit modern legacy-free platforms onto small form factors without protruding beyond the allowed board outlines with ‘wings’. With the ISA bus, serial ports and even the PCI bus no longer integrated into lowpower chipsets, it takes extra circuitry to meet the needs of many embedded applications. The ISM specification defines the board size, four fixed mounting holes, component height limits and flexible ‘expansion zones’ for I/O and/or bus connectors. The fixed corner mounting holes allow re-use of enclosures without modifications in the future.
ISM allows many combinations of bus and I/O connectors as long as those interfaces reside within the defined expansion zones. ISM also offers a choice of using right-angle connectors that overhang the board edges, or extending the circuit board if vertical/non-overhang connectors are used. ISM boards can be SBCs, stackable CPU and I/O cards, and even computer-on-modules (COMs). This flexibility allows easy migration from SBCs to COMs and vice versa, or from processor to processor, while preserving investments in mechanical designs.
SUMIT is one of many board-to-board expansion interfaces that are permitted with ISM. SUMIT, short for stackable unified module interconnect technology, offers PCI Express, USB, SPI, I²C and LPC Bus expansion using 52-pin, high-bandwidth, rugged Samtec Q2 series connectors. This mix of high-speed and low-speed buses simplifies the task of attaching many types of I/O without complex bridges and software.
An independent standards organisation called the Small Form Factor Special Interest Group, or SFF-SIG, creates, adopts and maintains a number of emerging standards for the low-power, small form factor market. As consumer technology is often inappropriate for the embedded market, the standards feature reusable modular building blocks, developed by embedded vendors for embedded OEMs. Many of these are optimised for ultra low-power processors and controllers, yet scale up to multicore processor environments. The ISM and SUMIT standards fall within this organisation’s purview.