Abstract: An apparatus is provided for performing testing of at least a portion of a system under test via a Test Access Port (TAP) configured to access the system under test. The apparatus includes a first processor for executing instructions adapted for controlling testing of at least a portion of the system under test via the TAP, and a second processor for supporting an interface to the TAP. The first processor is configured for detecting, during execution of the test instructions, TAP-related instructions associated with control of the TAP, and propagating the TAP-related instructions toward the second processor. The second processor is configured for receiving the TAP-related instructions detected by the first processor and processing the TAP-related instructions. The first processor is configured for performing at least one task contemporaneously with processing of the TAP-related instructions by the second processor. An associated method also is provided.