|
|
假如在一个matchgroup中,有10个pinpair,由5个网络(net/xnet均可)生成,每个网络对应2个pinpair。1 R$ m) h, p2 U$ u( i) d7 n
那么如果你选择local 局部等长,那么虽然10个pinpair虽然在一个matchgroup中,但是匹配只会在同一net/xnet对应的那2个pinpair之间进行,和其他8个pinpair没关系,但是global的话就是全部10个pinpair均进行匹配。所以, 一般内存什么的延时设置都是global& Q0 l" a- u7 R$ `
4 p3 l E' k0 Q8 J3 `, N* t5 ^
PS,软件自身的参数/功能不确定,直接F1是最有效直接的,顺便给你看下帮助说明。
0 U" z3 H. l9 v# l! t" v5 h8 ~% I V. D) {) c' R8 E
With a Local scope, all pin pairs occupy a single Match Group; Constraint Manager compares pin pairs to only pin pairs in the same Xnet. In Figure 2-5, Constraint Manager compares pin pair U17.7:U10.12 only with pin pair U17.7:U11.12 because they come from the same Xnet, ADDR5.- Q5 Y2 B5 V7 B- n- g( `
With a Global scope, Constraint Manager validates pin pairs collectively in the (single) Match Group, as shown in Figure 2-6. In this scenario, Constraint Manager compares pin pair U17.7:U10.12 to all other pin pairs in the Match Group. |
|