A
neural processing unit (NPU) is capable of testing a component of the NPU in a running
system, i.e., during runtime. The NPU includes a plurality of functional components, each of which includes an
electronic circuit; at least one wrapper connected to at least one of the functional components; and an in-
system component tester (ICT). The ICT performs a selection of one of the at least one functional component, in an idle state, as a component under test (
CUT) and performs a test, via the at least one wrapper, of the selected functional component. The ICT may monitor states of the plurality of the functional components via the at least one wrapper, stop the test based on a detection of a collision due to an access to the selected functional component, and return a connection of the selected functional component to the at least one wrapper according to the stop.