Designing Circuit Boards for Test

As boards become more complex the ability to test with traditional methods and systems becomes more difficult. In some cases, the boards and their components are so dense that revolutionary test methods are necessary to provide adequate fault coverage and diagnostic ability. This is particularly true where BGA technology is selected and it is necessary to test the board using virtual test points. The design then needs to be analyzed to understand the degree of fault coverage under these design conditions. Design For Test is where component selection and circuit design are evaluated for their testability during the development process.

Philosophy

DFT not only helps design engineers avoid wrong or weak implementations of boundary scan, but also helps utilize multifaceted benefits of boundary scan in testing products and programming devices. .

Where a commitment is made to boundary scan ö an effective DFT strategy is intended to help prevent engineering changes, which may result if testability is not adequately addressed earlier during the design cycle. With boundary scan becoming a central process in many board test and programming applications, attention to DFT and adherence to proper design practices has become essential for successful launch and production of many new products

Boundary Scan test development, using JTAG provision application software

The combination of JTAG ProVision and JTAG Visualizer give you unequalled support in preparing boundary-scan tests and ISP applications. Even if you're new to boundary-scan, or if you've been away from the tools for awhile, you'll quickly be developing complete routines for your boards.

JTAG ProVision's wizard and model library guide you step-by-step through the process. The built-in coverage examiner delivers critical feedback so that you know how to achieve your DFT objectives and when you've achieved them. 

JTAG Visualizer is like nothing else in the industry:  with it, you can see your boundary-scan applications and results right on the schematic and layout drawings of your board. When you're done, you can easily port your applications to your company's production department or to your contract manufacturer.