Abstract: The present invention provides a method, apparatus and program product for providing controlled access to and/or exit from a portion of a scan chain. The method, apparatus, and program product take advantage of a first controlling device placed within the scan chain prior to the portion of the scan chain to be controlled, a second controlling device placed within the scan chain just after the portion of the scan chain to be controlled, and an access control mechanism coupled to the first controlling device and the second controlling device, wherein the access control mechanism controls access to and/or exit from the portion of the scan chain between the first controlling device and the second controlling device. The access control mechanism selectively allows access to and/or exit from the protected portion upon receipt from an instruction from a routine, wherein the routine is only accessible to an authorized user.