TM4C1294NCPDT: USB electrical connection

Barak Dror said:

1) Since I dont plan to support OTG, do I need to use the USB0ID pin (pin 95) ? can I use it as GPIO?

Yes, you can use as GPIO if you are not going to use OTG mode.

Note: When used in OTG mode, USB0VBUS and USB0ID do not require any configuration as they
are dedicated pins for the USB controller and directly connect to the USB connector's VBUS
and ID signals. If the USB controller is used as either a dedicated Host or Device, the
DEVMOD field in the USB General-Purpose Control and Status (USBGPCS) register can
be used to connect the USB0VBUS and/or USB0ID inputs to fixed levels internally, freeing
the PB0 and PB1 pins for GPIO use. Note that PB1 (USB0VBUS) is a 5-V tolerant signal as
required. For proper self-powered Device operation, the VBUS value must still be monitored
to assure that if the Host removes VBUS, the self-powered Device disables the D+/D- pull-up
resistors. This function can be accomplished by connecting a standard GPIO to VBUS.
The termination resistors for the USB PHY have been added internally, and thus there is
no need for external resistors. For a device, there is a 1.5 KOhm pull-up on the D+ and for
a host there are 15 KOhm pull-downs on both D+ and D-.

Barak Dror said:

2) Must I use the USB0VBUS pin or can I use it as GPIO?

Same as above.

Barak Dror said:

3) does the connection for the USB0DP/DM is direct from pin to connector or do I need to use termination? (I'm not speaking of protection diodes).

Please refer to the TM4C129 System Design Guideline section 4.3 for details about DM/DP routing and impedance matching. https://www.ti.com/lit/pdf/spma056. Also make sure you have 100ohm in series on PB1 if you are in Device Mode only. Refer to section 4.3.1.