Preparing the production of our newer prototype (XIOHv5)
OpenHardware version5) and is still developed using 10-layers BRD file and 30+ pages of SCH (schematics) to handle the different blocks of the design and assemble them in one PCB. We have been doing several optimizations and features adding :-removing one DIMM of DDR2-using a MSP430 micro-controller to handle the power-sequence (critical feature for the boot of the CPU EP80579)-space optimization for the power supply and connectors-changing the format of certain connectors (i.e. UART RS232 to an RJ45 connector)
Please find below a screenshot of our BRD file (board file in Eagle 6.2) showing the PCB and displaying the polygons for certain layers
Polygons are signal, power and ground wires that assemble zone of wire to simplify the design and have wires to handle some currents needs on some power rails that we have. The power rails are numerous on the board and they should respect the current level needed by each block diagram (we will make an up-coming on the power rail organization) and namely the SoC that carries different functionnal block such as MAC, USB, RAM, UART, and TDM controller.
The design of these polygons take some times and should checked to be sure that we don't multiply signals by making polygons of the same signal with different names. For instance, all GND (ground) polygons should be connected and named the same.
Once the board and schematics had been finalized and checked (and double-checked), we did process FAB files for the PCB manufacturing and below you can see the picture of our PCB on top of a stack of PCBs ready to be assembled with the 1000+ components and 150+ different references of parts.
Prior to do the assembling in factory, we need check the package for each of our references and do a BoM (Bill of Materials) optimization to handle nicely our stock.</p>