Multiple drivers error while connecting mmcm clocks to MIG

[thisisobul]

hai

i am using ml605 board, and i want to interface ddr3 ram with MIG, the MIG requires two clocks (200,400 MHz). so i generated from MMCM and interfaced to MIG then the error comming as the both clock lines has multiple drivers. i tried to solve by seeing other threads but its not happened. please give me solution

i tried the mmcm with and without output buffers

if i put output buffer error comming as multiple buffers in one line

if i remove buffer then error comming as line has multiple drivers

thanks...

[vuppala]

Hello,

I suggest you to check the Technology schematic when the error was multiple buffers in one line.

Then write the buffer_type constraint on that specific net. 

If using ISE, see the section buffer_type in the following user guide: http://www.xilinx.com/support/documentation/sw_manuals/xilinx14_7/xst_v6s6.pdf

If using Vivado, see http://www.xilinx.com/support/documentation/sw_manuals/xilinx2014_4/ug901-vivado-synthesis.pdf

Thanks,

Vinay

[smarell]

Refer to the below threads for some inputs in resolving this error-

http://forums.xilinx.com/t5/MIG-Memory-Interface-Generator/Spartan-6-PLL-gt-MCB-Buffer-in-Series-problem/td-p/481160

http://forums.xilinx.com/t5/MIG-Memory-Interface-Generator/NgdBuild-455-Multiple-drivers-error-related-with-DDR2-clocking/td-p/484152

[vsrunga]

Hi,

You can use MMCM with in MIG and derive required clocks so that it save additional MMCM. 

Please check below link and follow the suggestions for modifying the RTL

http://www.xilinx.com/support/answers/35242.html

http://www.xilinx.com/support/answers/43559.html

 Hope this helps

-Vanitha