Abstract: A method for calculating switching interface activity format (SAIF) for a circuit design includes segregating the circuit design into a plurality of hardware look up tables (LUTs), inserting switching interface activity format (SAIF) counter logic, and inserting a multiplexer between the LUTs and the SAIF counter logic. The SAIF counter logic includes shadow logic, at least one counter, and memory. The method further includes (i) selecting a previously-unselected LUT by switching the multiplexer to the selected LUT, (ii) executing a test through the selected LUT and the SAIF counter logic to generate SAIF data for the LUT, (iii) storing the SAIF data for the selected LUT in the memory, and (iv) continuing with (i) through (iii) until each of the plurality of LUTs is selected. The method further involves merging the SAIF data from each selected LUT into a consolidated SAIF file with SAIF data for the circuit design.