Design Compiler再了解(四)

一個抽出的範例
Wire Load Model

wire_load (“10x10”) {

resistance : 5.0

capacitance : 1.1

area : 0.05

slope : 0.5

fanout_length (1, 2.6)

fanout_length (2, 2.9)

fanout_length (3, 3.6)

fanout_length (4, 3.9)
fanout_length (5, 4.1)
fanout_length (6. 4.7)

}

Wireloadmodel的作用
•Estimate capacitance/resistance of nets.
•Statistically average length of a net for # of
fanouts.

Length = 4.7+((8-6)x 0.5) = 5.7 length
Capacitance =5.7(length) x1.1 (cap coeff.)=6.27 load units