关于spartan6下DDR2的操作，可以看一下我的博客。

菜鸟要飞

回复 9# shiyinjita


   文波两百多毫伏

菜鸟要飞

回复 9# shiyinjita


   复位信号外接一个按键

574920045

回复 10# shiyinjita


    是我的时序理解错了，按照手册上的来，就搞对了，不过手册的时序还是不详细！

574920045

回复 10# shiyinjita


    吉他哥又得麻烦你了，工程中建立好之后，我暂时没有进行管脚分配，编译的时候在map过程中会报错，我从pll中分出了二个时钟输出给外部管脚，之前一直报错后来加上ODDR2+OBUF然后输出给外部，但是我在map的时候一直报ERRORack:1107 - Pack was unable to combine the symbols listed below into a
   single IOB component because the site type selected is not compatible.
的错误，不知道为什么。难道我的ODDR2和OBUF用多了？还是别的原因？补充：我的UCF文件管脚约束文件一直没有加！因为我暂时没有进行管脚分配！

shiyinjita

回复 14# 574920045


   这个问题忘记了，但是这样用是没有问题的我当时也是用DDR2的时钟来分频作为全局时钟的

shiyinjita

回复 12# 菜鸟要飞


  感觉电压的缘故

fjelly

先顶一个，进去看看那

ra3d

先顶一个，进去看看那

Jasen_0314

谢谢分享

qd0090

回复 1# shiyinjita


    你好，帖子地址已经找不到了。
    我在使用MIG的时候，map出现如下错误：
Place:866 - Not enough valid sites to place the following IOBs:
IO Standard: Name = LVCMOS25, VREF = NR, VCCO = 2.50, TERM = NONE, DIR = BIDIR, DRIVE_STR = 12
IO
This may be due to either an insufficient number of sites available on the device, too many prohibited sites,
or incompatible I/O Standards locked or range constrained to I/O Banks with valid sites.
    This situation could possibly be resolved by one (or all) of the following actions:
a) Grouping IOBs of similar standards into a minimum amount of I/O Banks by using LOC or range constraints.
b) Maximizing available I/O Banks resources for special IOBs by choosing lower capacity I/O Banks if possible.
c) If applicable, decreasing the number of user prohibited sites or using a larger device.



Place:382 - The placer was unable to find a feasible solution for the IOBs in your design. This is possibly due to SelectIO banking constraints.
Each Group of a specific Standard is listed.
Standard SSTL18_II (Vref=0.90 Vcco=1.80 Terminate=none) 39 IOs, 39 locked.
  (0-Inputs, 23-Outputs, 16-Bidirectional)
Standard LVCMOS25 (Vref=NR Vcco=2.50 Terminate=none) 9 IOs, 7 locked.
  (1-Inputs, 7-Outputs, 1-Bidirectional)
Standard DIFF_SSTL18_II (Vref=NR Vcco=1.80 Terminate=none) 6 IOs, 6 locked.
  (0-Inputs, 2-Outputs, 4-Bidirectional)
Standard LVCMOS18 (Vref=NR Vcco=NR Terminate=none) 3 IOs, 3 locked.
  (3-Inputs, 0-Outputs, 0-Bidirectional)
Bank Summary
____________
If an IOB is placed in a dedicated Vref site, it will be indicated by the word 'Vref' at the end of a summ...
NOTE: This message is very long (~7 K) and has been shortened to a maximum of 1000 characters for viewing in this context.
           Please refer to the corresponding ASCII report for the full message.
能帮帮我么？谢谢！卡了我好几天了。