This is my first "real" design, a (more or less) universal USB serial interface board with two RS-232 ports, one RS-485 and one CAN interface. Hi-res schematics, top and bottom PCB layers with bottom copper pour turned off. Each FT2232 channel has two interface drivers (a RS-232 and either RS-485 or CAN) that can be connected to it with jumpers. Jumper wires can also be used for e.g. SPI or JTAG modes supported by this chip.
I used a FT2232 breakout board from dangerousprototypes.com (can't post a link) as a reference (not for layout though). Layout is what I'm most concerned with here. I tried to implement most of the good advice I found on this site, such as the ground plane (disabled), power trace along the perimeter on the bottom layer, power polygon under the chip, short traces for oscillators and decoupling capacitors etc. The area of the FT2232 seems much more complicated and cramped than on the dangerousprototypes board. I wonder if that's or because their schematics is simpler and crystal / capacitors are placed farther from the chip, or because I suck at this. (In hindsight, placing some components on the bottom layer would probably simplify the layout.)
I tried to comply with requirements of the seeedstudio.com manufacturing service.
(There's a discrepancy between schematics and layout in pin header placement - RS-485 and CAN headers are swapped.)
I'll appreciate any critique or advice.