Rapid Development with HW Building Blocks: Reference Designs

Second in a series…..

In the first post in this series we looked at using System on Chip technology to save time in developing an embedded system.  In this posting we look at the use of hardware reference designs.

Another resource that can save development  time is a reference design that uses components you want to use in your system.  These reference designs are typically provided by a semiconductor vendor but were designed by a third party.   A good reference design will at least include a working board, schematics, and physical design files that allow you to build your own hardware based on a working design.  This can be a real time saver.  Occasionally the source schematics are included and if you use the same schematic capture tool you can save a lot of time that would have been spent creating symbols and drawing schematics.  Most often though the schematics are in PDF format.

Sometimes you can get low level firmware, software drivers, codecs, or even higher level software included in a reference design.  A good reference design board will allow software developers to get going with a lot of their low level software and firmware before actual hardware development.  A working reference design board can also allow experimentation and verification of things like a critical task’s real time performance capability, boot up and reset issues, and power and thermal issues. There are tests you can run in seconds on a lab bench that are not practical in a hardware simulator.

There are important issues to consider when using a reference design.  A thorough design review of the reference design is necessary to avoid problems later on. The  assumptions for acceptable design practice made by the developer of the reference design  may not be the same as yours.  Find out this stuff up front, not via a call from an angry customer.  Also, carefully check any licensing issues or terms and conditions for copying a reference design.  Hardware licenses can be different than software licenses because they are based on  patent law not copyright law.  It’s important to know the difference.   A patent based license can control the use and manufacturing of your device based on their design documentation.   A copyright based license just controls the distribution of the design documents.  Having a lawyer review the license up front is always a good idea.