We have created an automated characterization process for the DETFFs using perl and GSPICE (a SPICE pre/post processor).  Characterization for timing and energy was done on the SPGFF using the trip points in the 0.18um library at the nominal conditions (1.8V, 25°C).  The characterization methodology can easily be extended to include the best and worst case corner models over temperature and supply variations.  Non-linear tables were created for drive characteristics, setup and hold, and energy which the tool then uses to extrapolate the needed data points. 

Below are the results of characterization for both the SETFF (the TGMS) and the DETFF (the SPGFF).  Figure 1 shows the results of delay vs clock slope and load.  As shown in the figure, the area of typical operation for the SPGFF has slightly better delay than the TGMS.

Figure 1 - Characterization of the SPGFF and the TGMS showing the data to Q delay for each flip-flop over varying loads and clock slopes.

Figure 2 shows the energy characterization results for the SPGFF and the TGMS.  As shown in the figure, the energy is comparable for both devices.  This is evidence that we should see a clock power reduction of one half. 

Figure 2 - Characterization of the SPGFF and the TGMS showing energy over varying loads and clock slopes.