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本帖最后由 lvsy 于 2014-4-18 13:25 编辑 0 w: k6 z# c; b* N
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+ H% ^5 h+ Z0 ?& c最大输入延时如下定义:$ j/ C; r" x' l9 Z7 y8 H/ x
input delay max = Board Delay (max) – Board clock skew (min) + Tco(max)
9 V! y. o- d- g- s) v! \5 A, ~Altera官方资料是这样表达的:
" ?8 p# i; Z3 f& P, ?. iInput maximum delay= value maximum trace delay for data + tCO of external device – minimum trace delay for clock& s8 v- L" c+ j+ R* i3 @/ ?
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
* s5 K- A1 J/ V1 l: minput delay max = Tpcb(max) – (Tc2s(min)–Tc2r(max)) + Tco(max)就是成立的,你仔细体会一下。, q2 _' Y$ [# D
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同理得到最小输入延时:
6 o8 H$ ]( O$ z0 o+ B$ G1 uinput delay min = Tpcb(min) – (Tc2s(max)–Tc2r(min)) + Tco(min) ! L) X! C* A3 W
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0 h3 l+ e$ Q2 I& O5 H7 x
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