Civil Engineering Reference
In-Depth Information
linear program
The linear program is formulated under the assumption that the delays of the
combinational segments are constant. These delays can be calculated efficiently
by using the method of Section 5.2.1.
The above formulation may be altered to model uncertainties in the clock
skews. If it can be guaranteed that in the manufactured circuit‚ the skew at
flip-flop will be within the range where is the designed
value of the skew‚ then the difference between any skews‚ in the
manufactured circuit‚ must be within of the designed value of A
linear program that is guaranteed to produce a functional manufactured circuit
is formulated below:
An alternative formulation to maximize the tolerance of the solution to un-
predictable changes‚ for a given clock period
P‚
is as follows. This may be
achieved by maximizing the minimum slack over all the constraints‚ converting
the problem into a minmax problem. A new variable
M
is introduced‚ and
is added to each of the main constraint inequalities‚ so that maximizing
M
is
tantamount to finding the skew values that maxime the minimum slack over
all the inequalities. The precise formulation is as shown below:
