Hi Darrel,
I'm actually back on USB development, there is quite a bit of new stuffs! your USB_ASM_Service routine is very exciting.

If I understand correctly the timing issue will also "kill" I2CRead/Write, Shiftin/Shiftout, LCDout... There's hardware modules for SPI and I2C, even if they are not used by these instructions. However there's not much solution for driving the LCD.

Is the delay introduced by the interrupt that long? I mean, some processes does not require an extreme regularity of clocking/data signals, an intelligent LCD display should probably cope with this.

However I haven't been able to experiment with it yet... I have managed to compile and run successfully the DCD demo on a PIC18F13K50. Adding the USB_ASM_Service routine and commenting the USBService/USBInit in the demo makes the board unable to declare itself anymore.

I've also tried running both the interrupt and polled USB servicing to display the status of "PLUGGED" on a LED but nothing happens. The rest of the demo works fine though.

Any lead for this issue?
Thanks in advance for your time