How do I configure this ULPI component's speed?

[hobbskw]

I found this ULPI interface:

https://www.mouser.com/ProductDetail/Texas-Instruments/TUSB1210BRHBTQ1?qs=asCBFxFfL1Rp81qa4OEGqg%3D%3D

It says it supports low, full, and high speed. But, I cannot figure out how to tell it which one to use. I want to use low or full speed so I can add a USB isolator (isolators don't support high speed, as far as I can tell). Does anyone know how to go about doing this?

It will be interfacing between the USB and a Zynq-7000 SoC, which uses its MIO pins for the digital ULPI signals.

 

[FvM]

Did you review the register map in the datasheet?

 

[ser_g]

default XCVRSELECT=1 =12mb/s

 

[ser_g]

The host (or hub) uses a simple trick to decide whether to communicate with the device in full-speed (12MB/s) or in low-speed (1.5 MB/s). A full-speed device has a pull-up resistor of 1.5kΩ to 3.3V on the D+ line, whereas a low-speed device has the pull-up of 1.5kΩ on the D- line (both the 1.5kΩ and the 3.3V are nominal values). Once the host senses what kind of device is attached, it transmits its packets at the correct frequency.