DDR 的地址镜像是怎么回事，哪位大佬给解释一下？

毛豆盛宴

最近设计的板子要正反表贴，CPU支持地址镜像，请问DDR 的地址镜像还没搞清楚，不太敢用啊。是不是声称符合DDR协议的芯片都支持镜像功能呢？还有使用地址镜像的好处有哪些啊？多谢多谢
1 L$ x; J  s8 D0 G0 A

毛豆盛宴

哪里能查到资料呢？给个方向也行啊

毛豆盛宴

:):)

超級狗

DDR4 Module Address Mirror
) Y. ~; b9 k: |5 k4 q" Y* C


! e4 I. c" c: Z
* [* b- @: T0 b" z7 q/ D2 K

超級狗

洋人的說法︰
" q* c. Y+ E. }. [, MThe pins on the DRAM are defined in a manner that allows for these short trace lengths. The CA bus pins in Columns 2 and 8, ignoring the mechanical support pins, do not have any special functions (secondary functions). This allows the most flexibility with these pins. These are address pins A3, A4, A5,A6, A7, A8 and bank address pins BA0 and BA1. Refer to Table ... Rank 0 DRAM pins are wired straight, with no mismatch between the connector pin assignment and the DRAM pin assignment. Some of the Rank 1 DRAM pins are cross wired as defined in the table. Pins not listed in the table are wired straight.
+ b/ T! W# N2 S5 ^4 @/ {

毛豆盛宴

超級狗 发表于 2018-8-8 08:54
- ^* D* D% a; E4 a" |% l' G# }2 g% _; M洋人的說法︰
The pins on the DRAM are defined in a manner that allows for these short trace lengths ...

版主，亲自答疑解惑，多谢多谢。想想都有点激动呢，哈哈哈，我要好好去读读规范回来再给大家讲讲
6 l% ]$ j4 {3 Q9 S0 b" e6 X4 G

v3058703v

不错学习了

bedqmmoong

好处就是正反贴后fanout长度比较短，信号质量比较好

zmgan

谢谢分享，正在了解地址镜像相关的用法