system on module
{{short description|Board-level circuit that integrates a system function in a single module}}
{{more footnotes|date=December 2016}}
A system on a module (SoM) is a board-level circuit that integrates a system function in a single module. It may integrate digital and analog functions on a single board. A typical application is in the area of embedded systems. Unlike a single-board computer, a SoM serves a special function like a system on a chip (SoC). The devices integrated in the SoM typically requires a high level of interconnection for reasons such as speed, timing, bus width, etc. There are benefits in building a SoM, as for SoC; one notable result is to reduce the cost of the base board or the main PCB. Two other major advantages of SoMs are design-reuse and that they can be integrated into many embedded computer applications.{{explain|date=September 2018}}
History
The acronym SoM has its roots in the blade-based modules. In the mid 1980s, when VMEbus blades used M-Modules,{{Cite web|url=https://standards.ieee.org/ieee/1386/2076/|title=IEEE 1386-2001 - IEEE Standard for a Common Mezzanine Card Family: CMC|website=IEEE}} these were commonly referred to as system On a module (SoM).{{cn|date=May 2022}} These SoMs performed specific functions such as compute functions and data acquisition functions. SoMs were used extensively by Sun Microsystems, Motorola, Xerox, DEC, and IBM in their blade computers.
Design
A typical SoM consists of:
- at least one microcontroller, microprocessor or digital signal processor (DSP) core
- multiprocessor systems-on-chip (MPSoCs) have more than one processor core
- memory blocks including a selection of ROM, RAM, EEPROM and/or flash memory
- timing sources
- industry standard communication interfaces such as USB, FireWire, Ethernet, USART, SPI, I²C
- peripherals including counter-timers, real-time timers and power-on reset generators
- analog interfaces including analog-to-digital converters and digital-to-analog converters
- voltage regulators and power management circuits
See also
- {{anl|CompactPCI}}
- {{anl|Futurebus}}
- {{anl|PCI Mezzanine Card}}
- {{anl|VPX}}
- {{anl|VXS}}
References
{{Reflist}}
{{refbegin}}
- ANSI/IEEE Std 1014-1987 and ANSI/VITA 1-1994
- [https://standards.ieee.org/ieee/1386/2076/ 1386-2001 - IEEE Standard for a Common Mezzanine Card Family: CMC]
- Standard ANSI/VITA 46.0-2007
- [http://opensystemsmedia.com/hall-of-fame/vita-technologies/pci-mezzanine-cards VITA Technologies Hall of Fame - PCI Mezzanine Cards]
{{refend}}