Source: EPS News
Understanding the risks associated with component selection during the design and product definition phases requires deep knowledge of the timeline for long-term system development and when components are introduced by the semiconductor company. Market misalignment occurs when a long-term system is designed using short-term market products or already mature products.
Architecture misalignment happens when the choice of processor architecture is clearly close to the end of life, usually when the cost of architectural change has postponed an inevitable future. Board design misalignment results after board layouts are done with knowingly, densely packed, shifting commodity products. Component selection during development is a deciding factor for potential premature product redesigns and requalification. Component choices are frequently influenced by the ongoing progress of product development, with the aim to maximize the potential of older software and hardware solutions.
Market misalignment: There are times when the easy or most efficient component selection is the wrong choice, due to market misalignment. This scenario could be feasible if there is a planned and budgeted last-time purchase within a few years of selecting the components, however, this is seldom the situation. For example, graphic driver products have a very short lifetime in comparison to military or commercial avionics displays. Opting for a PC-oriented component in a market where the sole purpose of those components is product development will lead to obsolescence even before the first production units are shipped for long-term systems. When it comes to choosing a graphics driver product upfront, it is crucial to consider the long-term system cost and allocate a budget for an early last-time-buy. This is necessary to safeguard military or commercial avionics displays and avoid obsolescence in a market where PC-oriented components may not meet the requirements of product development.
Architecture misalignment: Commercial avionics has long settled on the PowerPC processor multi-core architecture, due to the control for multi-core operation and speculative execution across multiple processor cores. The existing multi-core PowerPC products have been certified for commercial avionics and software development is proven. However, the end of the PowerPC architecture is on the horizon. It is only a matter of time before the commercial avionics market adopts ARM or RISCV as their architectures. Every single PowerPC-based product being designed today is already on a processor product line that is over a decade old.
Board design misalignment: There is always the temptation to pack DRAM as tightly as possible. Many systems have variable amounts of DRAM, to enhance their product or to provide tiers within a product family. Packing that DRAM into as small of a space as possible could be an advantage. However, the challenge with long-term systems lasting 15-20 years is that DRAM technology will evolve significantly within that time. It is crucial to anticipate this change by strategically designing board layouts upfront, minimizing needs for future modifications.
Market misalignment: Memory products are designed for short-term systems. The largest memory suppliers no longer stock DDR3. Coincidently, DDR3 is the primary memory type supported by the latest PowerPC product. Designing long-term systems without a long-term memory product plan upfront is an issue. Memory has been a fast-moving product for decades. Memory innovations come at a rapid pace to keep up with data center demands and portable product demands. Long-term systems are a market misalignment with all memory types because all memory types are short-term products.
Key questions to consider:
- What is the component’s lifecycle status across the application’s lifetime?
- Not only does the end-product’s lifetime need to be considered in component selection, but when the component’s lifetime started, as well as the product’s lifetime start dates and end dates must be accounted for. Choosing the right components means alignment of product dates with all component dates.
- Are the key components of the design comprehensively documented?
- Software is about 10x the cost of change versus hardware. Any component that is directly controlled by software will be the most valuable to keeping a long-term system shipping. These components are typically the highest price items in a BOM as well. The documentation and archive requirements associated with these types of components must be elevated to alleviate long-term system risk of sustainment.
- Can the true design files (VHDL, Verilog, Spice-Models, Constraints, Source Test-Vectors) be archived at the design phase to offer a chance of rebuild if the unexpected happens?
- This pertains to the most intricate, expensive, and software-dependent products. To minimize maintenance risks, it is crucial to create an archive that contains all relevant information about these products. This archive should be independent of any EDA tools and operating systems.
- Does the design contain proprietary intellectual property? If so, the ability to “port” such designs when the components are made obsolete may be compromised, or subject to relicensing and royalties.
- Embedded IP blocks, particularly within FPGAs and ASICs, are commonplace. However, these IP blocks can also make portability and sustainability almost impossible if efforts are not taken to ensure there is a plan for these products. This plan may have to be a fully funded last time buy or IP licenses up front that allow porting from one technology to another. Simply clicking a button and incorporating IP blocks (presumably because it’s easy to do so) is not a solid long-term system plan. If IP blocks are not incorporated into a long-term plan at the design phase, it may be impossible to come back to them years later for a solution.
Many companies do almost none of this planning for long-term systems in the design phases where the impact would be maximized. From component selection, all the way through IP block selection, there are many ways a long-term system company can mitigate risk and schedule for system longevity. Ultimately, partnering with and authorized distributor and licensed manufacturer such as Rochester Electronics to ensure long-term system availability is the best solution.