Algorithm to identify best Q-gating candidates and a Q-gating cell architecture to satiate the launch-off-shift (LOS) testing

A computer system for selective Q-gating flip-flops in a plurality of flip-flops contained in a design the computer system comprising:

• one or more processors, one or more computer-readable memories, one or more computer-readable tangible storage devices, and program instructions stored on at least one of the one or more storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, the program instructions comprising:
• program instructions to determine a maximum width value, a maximum depth value, and a maximum congestion value in the design;
• program instructions to determine a relative width value, a relative depth value, and a relative congestion value for each of the plurality of flip-flops in the design;
• program instructions to determine grade values for each of the plurality of flip-flops in the design based on a ratio between the relative width value, the relative depth value and the relative congestion value, and the maximum width value, the maximum depth value, and the maximum congestion value, respectively;
• program instructions to determine, based on the grade values for each of the plurality of flip-flops in the design, an overall summed value for each of the plurality of flip-flops;
• and
• program instructions to sort the plurality of flip-flops based on the overall summed value for the plurality of flip-flops according to magnitude.

A computer program product for selective Q-gating flip-flops in a plurality of flip-flops contained in a design, the computer program product comprising:

• one or more computer-readable storage devices and program instructions stored on at least one or more tangible storage devices, the program instructions comprising:
• program instructions to determine a maximum width value, a maximum depth value, and a maximum congestion value in the design;
• program instructions to determine a relative width value, a relative depth value, and a relative congestion value for at least one flip-flop in the plurality of flip-flops in the design;
• program instructions to determine grade values for each of the plurality of flip-flops in the design based on a ratio between the relative width value, the relative depth value and the relative congestion value, and the maximum width value, the maximum depth value, and the maximum congestion value, respectively;
• program instructions to determine, based on the grade values for each of the plurality of flip-flops in the design, an overall summed value for each of the plurality of flip-flops;
• and
• program instructions to sort the plurality of flip-flops based on the overall summed value for the plurality of flip-flops according to magnitude.