Boundary Scan Design for Testability (DFT) Guidelines
アプリケーションノート
As PCBAs continue to increase in complexity, ensuring adequate test coverage has become more challenging due to limited physical access and high device density. Boundary scan, defined by IEEE 1149.1 and extended by IEEE 1149.6, provides an effective method for improving testability at the board level.
This application note presents practical design guidelines for implementing boundary scan with a focus on achieving reliable chain integrity and effective test coverage. Key topics include daisy chain architecture, signal integrity, TAP signal distribution, device selection, and debug flexibility. Additional considerations such as multi-voltage domains, programmable devices, power management components, and multi-board configurations are also addressed.
The document further explores high-speed interface testing using IEEE 1149.6 and highlights the importance of verifying BSDL files to ensure correct device behavior. By applying these guidelines within the context of specific design constraints, engineers can develop robust boundary scan implementations that support efficient testing and simplify system-level debug.