c6678外接ddr3的疑问-图片在附件中。

C6678外接4片ddr3，阅读sprabi1b文档，存在疑问如下：

（1）       p21写有如下片段

Each trace to the respective  within 500 mils and the opposite side of the termination£termination should be  resistor should tie directly to the VTT rail.

疑问：上面写的500mils是指ddr3到另外一片ddr3的地址、控制信号走线长度不超过500mils么？

（2）p27写有如下片段

Address and command fly-by groups must have stubs less than 80 mils and be length-matched within +/- 10 mils.

疑问：请问80mil是指下图的哪段线的长度？

Allen35065：

1. 500mil指的是到terminal的长度；

2. stub的长度。