
evaluations per frame. The initial operation is an I=O read of the input u
n
¼u(t
n
). The next process is
the two derivative function evaluations including the calculations to advance the state from x
A
(n)to
x
A
(n þ1). Note that the time to evaluate the derivative function may be random due to the necessity
of searching through tables of empirical data or as a result of branching when the code is executed.
Lower and upper limits to compute the derivative functions and perform the calculations necessary
for updating the state are t
1
and t
2
s. The final operation is an I=O write to the hardw are interface as
shown in Figure 8.66. The residual time before