我看design rule,其中描述布线的部分5 r# Y- L& z& {5 F& l
Electrical class name Description restrictions* |/ i& m6 W0 V+ |; L
DIFF_SATA matched length traces to within 500um in combination Layer 1/2 only ,No stubs, match to 500um5 ~+ n6 P8 a2 Q# F8 w: S9 {! u8 u
with differential pairs SATA [0:3]_[T,R] * A) R2 c3 m7 K0 Q: E7 B& o
* {: O# a6 q# p8 z7 P1 {2 W* k请问这段是表示DIFF_SATA 走等长线不超过500um吗?那么Layers 1/2是什么意思?No stubs是什么意思? / A9 _# S. D S! _! `6 t0 _, T( x1 l4 Z& i6 h" E: r! A
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谢谢