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本帖最后由 lvsy 于 2014-4-18 13:25 编辑 / _9 h- t0 Z7 \ z
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$ S& M9 _* \7 Z$ ^' S( x: E7 K最大输入延时如下定义:9 I9 W' A2 w: `" e# {0 A- z
input delay max = Board Delay (max) – Board clock skew (min) + Tco(max)
6 R9 z7 A% G# RAltera官方资料是这样表达的:% [1 n4 C0 r" h/ W( k' a7 s9 m
Input maximum delay= value maximum trace delay for data + tCO of external device – minimum trace delay for clock
" l6 E" `# }3 Y& i+ e8 L: C# k9 K/ A1 S以你这个图来讲,Tpcb就是Board Delay, Tc2s-Tc2r就是Borad clock skew,也就是trace delay for clock,那么4 D! I% [4 ^, w' {
input delay max = Tpcb(max) – (Tc2s(min)–Tc2r(max)) + Tco(max)就是成立的,你仔细体会一下。
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5 t' o6 f7 U1 h1 m" Q, ?同理得到最小输入延时:
4 v; d4 n, e b" O6 G; z4 y4 yinput delay min = Tpcb(min) – (Tc2s(max)–Tc2r(min)) + Tco(min)
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