SANTA CLARA, Calif., 14 Oct. 2009. The Small Form Factor Special Interest Group (SFFSIG), a collaboration of suppliers of embedded component, board, and system technologies, announced the availability of revision 1.0 of the ISM (Industry Standard Module) and SUMIT-ISM specifications for small, rugged, stackable embedded systems.

The SUMIT-ISM specification documents the use of SFF-SIG's flexible SUMIT (Stackable Unified Module Interface Technology) interface on popular 90x96-millimeter stackable modules. The ISM specification provides an explicit form-factor-only definition upon which the SUMIT-ISM specification is built.

Since the SUMIT specification defines only a board-to-board interface (connectors and pin definition), the ISM Specification is necessary to define the form factor while the SUMITISM specification defines how SUMIT is implemented on ISM modules, says a representative.

In order to support a variety of legacy 90x96mm modules marketed as PC/104 or PCI-104 modules on a SUMIT-ISM stack, the SUMIT-ISM specification offers a level of flexibility to maintain compatibility.

Legacy bus support can be supplied by the CPU and maintained up the stack, or can be provided through a bridge module in the stack itself. With SUMIT-ISM, stackable I/O expansion is implemented using the SUMIT standard introduced by SFF-SIG in early 2008.

Through the inclusion of one or two 52-pin SUMIT connectors, a SUMIT-ISM CPU can provide PCI Express (up to 6 x1 lanes or 2x1 and 1 x4 lane), USB 2.0, LPC, I2C, and/or SPI interfaces to the SUMIT-ISM I/O modules. The SUMIT-ISM CPU designer has the flexibility to provide all or any subset of these interfaces.

In anticipation of the release of these specifications, SUMIT-ISM CPUs are already available from member companies ADLINK and VersaLogic.

SUMIT-ISM I/O modules are available from member companies VersaLogic and WinSystems.

The ISM and SUMIT-ISM specifications can be downloaded from www.sff-sig.org/sumit.html.