Apparatus for scan testing of integrated circuits with scan registers

摘要

In one embodiment of the invention, an apparatus for scan testing an integrated circuit is provided. The apparatus includes a combinational logic network; and a device for reducing gate switching in the combinational logic network to reduce power consumption during a scan test on the combinational logic network. The device for reducing gate switching in the combinational logic network includes a device for periodically isolating scan data from the combination logic network; and a device for periodically holding functional data coupled into the combinational network substantially steady. In one embodiment of the invention, the device for reducing gate switching in the combinational logic network is a plurality of serially coupled scan registers each having a pair of opposed controlled outputs with one controlled output providing scan output data and another controlled output providing functional data to the combinational logic network.