Can someone explain me the difference between USB and ULPI?
I know they are closely related but how they are related that not clear to me.
First time I came to know when I was looking at this board (See at the bottom middle):
Xilinx Zynq-7000 All Programmable SoC ZC702 Evaluation Kit
Best Answer
USB defines the external interface (physical, electrical, various layers of signalling).
The PHY (physical interface circuitry) that presents USB interfaces also has to interface to the host computer. This is done using a UTMI interface
ULPI is a lower pin-count version of that internal interface. This is beneficial for smaller and lower-cost devices.
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See http://www.ulpi.org/