A Dynamic Reusable Structure of I/O Pads for Scan Chains

With the increasing complexity of integrated circuits, there is a serious mismatch between the number of I/O pads and scan chains. To solve the above problem, this paper presents a reusable structure of I/O pads for scan chains, which can reallocate I/O resources dynamically and achieve an optimal state after chip manufacturing. The I/O pads and the input/output of the scan chains are connected through the scan I/O reuse logic, which is controlled by the configure chains in the tap controller. Therefore, the scan I/O reuse logic can be dynamically gated by configuring the tap controller.