DDR SDRAM地址问题

sunyuanxin

在Data Sheet中是这么描述的：
A0~A12 Address inputs provide the row address for ACTIVE commands, and the column address and auto precharge bit(A10) for READ/WRITE commands, to select one location out of the memory arry in the respective bank. A10 smpled during a PRECHARGE applies to one bank(A10 LOW, bank selected by BA0, BA1) or all banks(A10 HIGH). The address inputs also provide the op-code during a LOAD MODE REGISTER command.
  也就是说，A0~A9，A11~A12共12位复用行地址和列地址，通过CAS和RAS信号来区分当前输入的是行还是列。A10是预充电的控制位。但是行、列地址是否都要用12bit来表示？记得以前看过DDR SDRAM资料说行数比列数多得多，这样的话地址是怎么分配的？

jy8312

据我所知行列地址都不一定用12bit表示，根据不同的内存颗粒，位数都有区别。

woyao3g

正在学习这个，感觉学这个挺难的。

sunyuanxin

看到了，芯片手册上有，A9～A0是column address。