In an age where technology is king, electric systems have become part of everyday life. From our smartphones to medical equipment every piece of technology has been able to advance, thanks to rapid changes in how we work with electric systems. Innovation and creation are only able to be implemented in society if they have been tested and proven to work.
At first testing started with what is known as a “functional test.” This test runs through the system replicating the target application throughout the whole board. However, this type of testing has several problems. One is that it can be difficult to get an accurate enough set-up to where it is close enough to the intended system. If it does not match the target, then it is not enough to prove that the application will run as it is intended too. If this is not enough, all potential angles have to be run. These different scales of measurement range from basic to complex. Somewhere around the middle of the scale, the testing cannot function properly.
The next solution was a structural test which works intensely with the hardware of the application. This test breaks down the board into smaller, more manageable sections. These smaller portions means that targeted testing can look for more potential holes than in a functional test. Structural testing still has flaws, the main one which comes about with regards to accessing the hardware itself. The traditional “bed of nails” tactic can be costly to acquire and require precision: which can be difficult to achieve with many nodes. These problems are only increased with the rapid acceleration of technology which now has multiple boards layered together to compose a single system. Therefore, accessing the nodes becomes practically impossible rendering structural testing pointless in many applications.
Boundary scan technology started by applying testing areas to the boards as they were being manufactured. This not only ensured a place for testing but allowed it to be easily accessible. These testing spots all connect in the order in which they need to be tested resulting in a single output zone and a conclusive boundary scan cell operation. Multiple boards are no longer a problem because they can all be chained together, replicating the needed cycle.