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Fromto和Pin pair的含义不完全一致：
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The Difference Between From-Tos and Pin Pairs 4 e* `7 H( Y8 e6 e n
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Often times, from-to relationships can be confused with pin pair designations. To better understand these separate design attributes, please refer to the following definitions:
7 a, I1 H# ^1 V7 U •Net line ordering/from-tos - Ordered, physical pairings of component pins that instruct the router where to etch from and to when creating physical transmission lines (traces).
$ V, f: a7 f& y" C O8 Y •Pin pairs - Electrical pairings of component pins that are created for the purpose of defining electrical relationships between component pins in the form of constraints.
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" o7 [( H) n! ]只有定义了Pin pairs，才会生成虚拟节点(Virtual Pins)，也就是你说的T点——d，这样CES才能识别同一trace中的不同区段，才会显示各区段的长度；; r4 ^( x; ~' K/ d9 Q
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单纯定义From-to的话，即使实际走线是拓扑结构，CES只识别两个pin之间的trace长度，而忽略拓扑。 |
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发表于 2013-6-20 14:03
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