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.

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.

Abstract: A data processing system, integrated circuit device, program product, and method thereof utilize a service interface to provide external access to a plurality of cores integrated into an integrated circuit device. The service interface, which may be utilized to perform external data transfer through a service access port in connection with a predetermined service operation, is separate from any function interface that is utilized during regular operation of the device. The service interface includes a plurality of core interface units integrated with selected cores on the device and coupled to the service access port through a master interface unit that is configured to request at least one of the core interface units to initiate execution of a predetermined service operation.

Abstract: A tristate driver/receiver test circuit and an improved method are provided for parametric testing of variable voltage and variable impedance tristate driver and receiver circuits. The tristate driver/receiver test circuit includes a plurality of tristate driver/receiver pairs. The plurality of tristate driver/receiver pairs represent a plurality of parametrics including multiple voltage and impedance levels. A decoder having an input and an output enables one of the plurality of tristate driver/receiver pairs. The decoder output includes a plurality of decoder output lines. Each decoder output line is coupled to a respective one of the plurality of tristate driver/receiver pairs. Parametric select inputs are applied to the decoder input for selecting one of the plurality of tristate driver/receiver pairs. In the testing method, a first parametric test is performed. Then checking for special parametric tests is provided.