Technique to choose BGA pins

[Veronika]

In my project I need to connect FPGA (1156-pin BGA) with 204-pin DDR3 memory. I am confused, because there is a small area under BGA for big amount of signals. 11 raws of BGA are used. I am using PADS Layout.

Is there any helpful technique to set the pins in DxDesigner in more logical way in order to have straight connections in Layout?

And how can I solve (count) how many internal signal layers I need at the moment for my design?

I have never designed such complicated and multi-layer system. It is difficult even to start because I do not know where should I start from.

Help me please!!!

Thank you in advance for any responce!

Veronika

 

[marce]

https://www.mentor.com/products/pcb-system-design/resources/bga-breakouts-routing/
download PDf version its free, this will give you a lot of backgroundinfo on routing BGA's

 

[Veronika]

Thank you for your help!

 

[kabaleevisu]

how many layer do you have ???

route datasignal and address signal seperate layer

 

[Veronika]

The amount of signal layers depend on routing the breakout of BGA.. I need to use as fewer layers as possible. At the moment I have 4 inner signal layers.