Recently, our client has asked us to add USB support to an already existing design based on the Mega32 microprocessor. We decided upon the FTDI FT232R chip to drive this communication. The schematic for this chip is taken directly from the 232R datasheet for "self-powered configuration". Unfortunately, I have been unable to communicate with the chip. When I power on the unit, windows detects a usb device, but is unable to figure out what it is. Using USBView, I found that no information is being returned by the FTDI chip, and connection status is listed as "DeviceFailedEnumeration".
I've probed all the incoming voltage levels. VCCIO and VCC are tied to 5V, Reset# is sitting at 3.5V, the 3.3V output is at 3.3V, and grounds are at ground. I am also able to see some communication on the USBDM and USBDP lines, although my scope isn't fast enough to really see the signals. Does anyone have any experience with debugging this chip? I notice that the old BM model allowed you to check if the oscillator was operating properly, but I can't find that mentioned for the R model. At this point, the only thing I can think of is that the chip could be bad.
I've attached the schematic for this chip, I'd appreciate any thoughts you guys might have.