An integrated circuit includes a semiconductor die having a plurality of input/output pads. A plurality of boundary scan cells, one corresponding to each input/output pad, implements boundary scan functions associated with respective input/output pads. Each of the boundary scan cells includes a TDI input and a TDO output. The boundary scan cells are structured as a shift register to shift data from one boundary scan cell in a direction unilaterally to an adjacent boundary scan cell. A first boundary scan cell is the first boundary scan cell of the plurality of boundary scan cells to receive data. A last boundary scan cell is the last boundary scan cell of the plurality of boundary scan cells to receive data. An endless control conductor forms a loop proximate the plurality of boundary scan cells. The endless control conductor is coupled to each of the plurality of boundary scan cells to provide a test clock signal thereto. At least one other control conductor extends around the semiconductor die proximate the plurality of boundary scan cells. The at least one other control conductor is discontinuous between the first and last boundary scan cells. The invention can also be implemented at the system level.