Virtual reconfigurable scan-chains on FPGAs for optimized board test

Abstract

This paper presents a method for optimization of board-level scan-test with the help of reconfigurable scan-chains (RSCs) implemented in a programmable logic of FPGA. Despite that the RSC concept is a well-known solution for scan-based test time reduction, the usage of RSC may lead to un-acceptable hardware overhead. In our work, we are targeting a completely new approach of exploiting on-board FPGA resources that being unconfigured are typically available during the manufacturing test phase for carrying out tests using temporarily implemented virtual RSC structures. As the allocated FPGA logic is re-claimed for functional use after the test is finished, the presented method delivers all the advantages of RSCs at no extra HW cost. Experimental results show that the proposed virtual RSCs can fit into all available commercial FPGAs providing a significant overall test time reduction in comparison with traditional Boundary Scan approach.