TABLE OF CONTENTS The characterization process can be simplified in several ways in what concerns the simulation of Type 2 collisions. The simplification depends on the method chosen to obtain each parameter ? Si. from the n specific parameters ? Sij having j = 1, ..., n. We analyse several alternatives:
Alternative 1: We obtain all the parameters ? Sij and calculate the average, which will be used as value ? Si:
| (5.22) |  |
This alternative is the best approach because all the parameters substituted by the unique value are considered, but the characterization process is not simplified since it is necessary to continue calculating all the parameters and to simulate all the possible collisions with degradation.
Alternative 2: We calculate the average using the values corresponding to the first and last inputs:
| (5.23) |  |
The value obtained with this equation is also an intermediate value, since the parameters usually have a slightly growing tendency with the input index. The characterization process is simplified with respect to the exhaustive characterization for gates of three or more inputs, needing to simulate 3 n different collisions for each gate.
Alternative 3: As already mentioned, the difference of ? Sij parameters for variations of j is very small. The simplest method, which practically conserves the same precision as the previous ones, consists then of approximating the group of parameters by any one of them:
| (5.24) |  |
Any chosen value for k will lead...
