XE/XU-216 without USB PHY Topic is solved

[RitchRock]

Hello,

Thus far I only have experience with design for a USB device with the XE/XU-216 chip. I would like to use the chip in a stand-alone application without USB PHY (for example, standalone ADAT to I2S). In the datasheet, section 10 describes the USB PHY. Should I simply leave all of these pins un-connected for this design? Thanks!

[fabriceo]

hi

if you leave them unconnected it means you would not use them in your application and you don't need them.
Then why not keeping the usb capability for your product, like for a firmware update in the field, or settings some parameters trough a CDC virtual com port
just some thoughts :)

that said, my understanding is that if you do not use the usb phy, then the corresponding one bit ports (E/F/G/H/I/J/K) becomes available on both tile.
hopefully we ll get an answer from the xmos team

[akp]

I keep the USB_RTUNE 43R2 placed and keep the rest of the pins NC. I don't know if the RTUNE is even needed if USB isn't used. But all the other functions work fine with it there, so I left it.

[RitchRock]

I keep the USB_RTUNE 43R2 placed and keep the rest of the pins NC. I don't know if the RTUNE is even needed if USB isn't used. But all the other functions work fine with it there, so I left it.

Thanks!