Electronic – Eagle PCB duplicating parts


I've recently designed a FPGA breakout board using an FPGA BGA package, and due to the lack of packages I had on hand, I got the BGA-256 and drew new symbols and updated the connections from scratch.

Everything was spot on until I started drawing the schematic – upon a quick spot check to the PCB layout, my one BGA had turned into two identically-oriented packages with identical airwires as well as identical pin consolidation within the BGA array.

Any ideas on how to correct this issue? I cannot delete the duplicate part because if I do, I receive the "No forward-/backward-annotation can be performed!" error. Here's the schematic:
enter image description here

Board with "cloned" device:
enter image description here

So, what I was trying to do is put two pairs (four FPGAs) of FPGAs together for bitcoin mining onto a DIMM-form card that can "hot socket" into a multi-socket backplane/motherboard that carries the I/O and interface devices.

To save space and prevent from cluttering the schematic excessively, I decided to only connect pins that I determined were needed for my setup, namely the configuration and power pins and certain pins from I/O banks 0 to 3. Mapping these pins would also give me a much clearer view upon routing.

This is why the FPGA symbol in the schematic is multi-grouped and not a standard shape or size. The larger symbol to the left is a representation of the DIMM edge connector that I will build these FPGAs to. The only connection I have made at the point of screen capturing was to tie low all appropriate grounding points on the edge connector and FPGA ballout.

At first glance, because I stated I was using two pairs, having second copies may seem to make my life easier; but instead of having two pairs in parallel, I would have two doing the exact same thing.

Best Answer

My hypothesis is that the FPGA in the schematic is drawn as multiple sub-components along the lines of U51A, U51B, U52C, etc. U52C was intended as U51C, that's the error. Even though there is only one sub-component of U52 present, Eagle adds the whole IC to the board.

** I've made up the designators U51 and U52. The images in the O.P. have low resolution, and the designators aren't readable. I'm guessing that slender vertical component on the left is the connector, and the group of components on the right is the FPGA split into multiple sub-components.