Research On Visualization Methods Of Boundary Scan Test Results

Board Test is throughout the entire life cycle of the PCB. Boundary-scan test isdeeply researched and widely applied increasingly, because it is a kind of efficient,quick and low cost test method, emerging in recent years. Currently, most of themainstream boundary-scan test software only provides the text results, and thenon-intuitive test results impede the tester giving an accurate fault diagnosis.Because of the lack, we present a visual interactive way to display the test results.Based on this, we expand the research surround visual display boundary-scan testresults and the following studies have been done:(1) Visualizing the test results. We use the test results and PCB designinformation to get the connections between the fault devices’ pin (fault map) anddisplay these in the two dimensions. In order to avoid the fault map connectionscross, we determine the planarity of the fault map. And then according to the faultmap we use line exploration to grid-less routing algorithm based on lattice todisplay fault map in two dimensions screen. At last, we use the above methodcomplete the design and implementation of the platform of visualization show testresults.(2) Flatten fault graph. Original planarization algorithm is impracticable toanalysis the actual fault graph. Therefore, we introduce an improved algorithmwhich can satisfy the limited conditions in real problem and make the fault graph ina plane.(3) Line exploration to grid-less routing algorithm based on lattice. To raiseefficiency, we introduce an line-exploring algorithm best on lattice. Firstly, drawthe cabling network based on the routable regional boundaries. Secondly, confirmthe routing code referring to the routing direction of the grid intersection. Finally,obtain the routing lattice based on the cabling network and routing code. Then wecan use the target driven line search routing algorithm and follow the routing latticeto find the path. When we meet the dead point during the process, we may use thedead center avoidance algorithm to look for existent access. At last, improve theexplored path to reduce the number of inflection point. The algorithm using explorepoint as little as possible to use nearly linear time to find a relatively optimalrouting path, and further optimization to the routing path. The paper comes up with the visualizing of the boundary-scan test results toremedy the lack of current software. It has some theoretical basis and applicationvalue. And the prototype system has been initially used in the actual project. Theprototype system may be a referential experience for people to develop visual boardtest software.