Synthesis of IJTAG Networks for Multi-Power Domain Systems on Chips

The high-volume manufacturing test ensures the production of defect-free devices, which is of utmost importance when dealing with safety-critical systems. Such a high-quality test requires a deliberately designed scan network to provide a time and cost-effective access to many on-chip components, as included in state-of-the-art chip designs. The IEEE 1687 Std. (IJTAG) has been introduced to tackle this challenge by adding programmable components that enables the design of reconfigurable scan networks. Although these networks reduce the test time by shortening the scan chains’ lengths, the reconfiguration process itself incurs an additional time overhead. This paper proposes a heuristic method for designing customized multi-power domain reconfigurable scan networks with a minimized overall reconfiguration time. More precisely, the proposed method exploits a-priori given non-functional properties of the system, such as the power characteristics and the instruments’ access requirements. For the first time, these non-functional properties are considered to synthesize a well-adjusted and highly efficient multi-power domain network. The experimental results show a considerable improvement over the reported benchmark networks.