Current market trends pressure industrial and defense companies to innovate product features while simultaneously reducing cost, schedule, and risk. As a result, a market for commercial off-the-shelf (COTS) computer modules has developed. These modules, often called computers-on-module (COMs) or systems-on-modules (SOMs), deliver COTS computing functions and save development time and cost for computing platforms. However, the COTS COM/SOM solution has several key disadvantages, including architectural constraints, increased power consumption, software development complexity, and cost. Modified COTS, wherein a proven COTS design is leveraged as a basis for customized requirements, can overcome these issues. Let’s discuss.
Problems with SOMs
SOMs provide obvious advantages, such as off-the-shelf availability, conformance to a specification (which, in theory, should allow easy upgrade paths and multiple source selection), and potential cost savings. However, there are also a number of disadvantages associated with SOMs and SOM vendors.
1. SOMs require an additional carrier board to operate. A SOM alone will do nothing. In order to implement a full system, a carrier board must also be designed and manufactured. This is an additional cost to the customer, who must either perform the design or contract another party to do so (either the SOM vendor or another company). The result is a two-board stack that may not be optimal in features, power, and/or cost.
2. Specs such as QSeven constrain SOM I/O. Such constraints on SOM connectors may result in underutilization of the processor’s available I/O features. For example, QSeven revision 2 does not provide a MIPI-CSI camera or MIPI-DSI display interface. Therefore SOMs with processors such as the Freescale i.MX 6 that include these interfaces cannot provide them without specification violations or adding additional connectors. This diminishes the advantages of conformance to a specification, such as multiple vendor sources.
3. Some SOM vendors don’t have in-house BSP/software support. Without in-house BSP support, most SOM users must contract a third party software house to provide and customize the BSP. This requires management of two external parties, ownership of any issues, and potential project delays resulting from a multi-company engagement. Non-optimal implementations can result. Past problem areas include reliable suspend/resume operation and dynamic power management.
4. Low volume customers are lower priority. Related to the business case of SOM vendors, customers with low volume requirements may not receive priority attention during design or acquisition over high volume customers.
Modified COTS Advantages
Modified COTS circuit designs start with a proven product, eliminate unnecessary COTS functions, and add the I/O functions required for the product. The vendor of the COTS board performs the design. Advantages include:
1. Integration into a single board. Whereas a SOM application requires the design of a carrier and results in a two board stack, modified COTS results in a single, optimized circuit board which lowers recurring cost and can decrease size and weight.
2. Utilize all CPU features; eliminate unnecessary features. A modified COTS board allows customers to implement (and pay for) only the feature set that is required for their project. Processor peripherals not supported by a SOM specification can be utilized and circuitry that may be inherently present on SOMs (such as Ethernet PHYs) may be removed from a modified COTS design. By including only necessary peripherals, architectural efficiency is achieved, which can lower recurring cost, optimize power and feature density, and simplify software design.
3. Start with validated design to lower risk and compress schedule. A modified COTS design begins with a pre-existing and pre-tested hardware, which often preserves critical placement and routing during modification. This lowers risk and accelerates completion schedule.
4. BSP software is leveraged. The COTS board’s validated BSP serves as a proven starting point for the modified COTS BSP. Unneeded drivers are removed and drivers to support new features are added. As a result, like the hardware design, development cost, schedule, and risk of software development are lowered.
5. Development platforms. COTS development platforms (DPs) enable early application development in parallel with the Modified COTS hardware design schedule. This accelerates software development timelines by using a platform substantially similar in hardware and software architecture and implementation to the Modified COTS product in development. And, such as with SECO USA’s Fury-F6 and Fury platforms, DPs come with engineering support to aid in development. Designing the software in tandem with hardware development may dramatically reduce time to market and back-end technical risk.
The modified COTS approach to circuit and device design versus the SOM approach enables shorter schedules, and lower cost and risk. modified COTS allows for optimized product features, a desired product look and feel, and minimized power consumption. Experts in embedded modified COTS, SECO USA operates within a proven process to deliver functional prototypes within 3-4 months while providing firm fixed price assurance. Further information about SECO USA’s products and engineering services.