Boundary Scan Advantages

Posted on May 1, 2019

Today’s consumer is provided a variety of options no matter what the subject matter happens to be.  At Flynn Systems we like to keep things simple by providing the best solution in boundary scan options.  Saving the consumer both time and money by avoiding trial and error software, Flynn’s boundary scan is no nonsense and gets the job done right the first time.  This article will highlight a few options that you may consider in your search.

The Comparison

Functional Testing has historically been the standard way to test electronic systems. This process entails exercising a system as it’s designed to be used in its desired application. Functional Test works satisfactory, but there were multiple drawbacks of conducting this process. It can be complicated to imitate a functional setup that replicates the end application. Also, adequately testing a moderately complex system can be very difficult.

Structural testing takes the functional test a couple steps further. Contrary to functional testing that tests systems as a whole, the structural test examines individual partitions. Structural testing is more thorough and also has the ability to test corner cases. Although structural tests are more meticulous than functional tests, they are far from ideal. One issue with structural testing is its inability to access internal nodes. A resolution for this issue is to use the Bed of Nails test, which employs a fixture with multiple electrical contacts touching on exposed metallic pads.

As circuit technology shrinks, the Bed of Nails test becomes obsolete due to the fact that there is a higher reliance on multiple layer boards. This test also makes it nearly impossible to access internal nodes that are packaged in ball grid arrays.

Boundary Scan Solution

Boundary Scan is an ingenious approach to structural testing, and a great solution to the problems listed above. Rather than completely relying upon mechanical connections for access, dedicated test circuitry is added to the system’s IC’s using registers that are inserted at the I/O pins. This makes it so the registers can observe data on the I/O pins and can be used to override drive signals and to provide test stimulus to the circuit. By stimulating and observing internal nodes, boundary scan provides a strong mechanism for accurate structural testing. It’s important to note the possibility of issues arising from lack of coordination between organizations. When implementing boundary scan, it’s crucial that all departments are working cohesively. The test group needs to work with the design team and suppliers. Most importantly, boundary scan software helps these teams work together seamlessly.

Flynn Systems is a global industry leader for automated boundary scan test and programming solutions, delivering IEEE 1149.1 and IEEE 1149.x compliant hardware, software, turnkey products and services. To learn more about our boundary scan test solutions, give us a call at (603) 598-4444 or visit our Products and Services page.