A device and a method for testing a connectivity between a first device and a second device, the method includes: writing, at a first frequency and in a serial manner, a first test word to a source boundary scan register; writing a content of the source boundary scan register, at a second frequency and in a parallel manner, to a target boundary scan register; wherein the second frequency is higher than the first frequency; reading the content of the target boundary scan register; wherein the source and target boundary scan registers are selected from a first boundary scan register of the first device and a second boundary scan register of the second device; and evaluating a connectivity between the first and second device in response to a relationship between the first test word and the content of the target boundary scan register.