User manual

Table Of Contents
Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 403
UG585 (v1.11) September 27, 2016
Chapter 15: USB Host, Device, and OTG Controller
The protocol engine is responsible for all error checking, check field generation, formatting all the
handshake, Ping and data response packets on the bus, and for generating signals that are needed
based on a USB based time frame.
Protocol Engine Functions
The protocol engine contains several functions for both host and device mode:
The token state machines track all of the tokens on the bus and filters the traffic based on the
address and endpoint information in the token.
The CRC5 and CRC16 CRC generator/checker circuits check and generate the CRC check fields
for the token and data packets.
The data and handshake state machines generate any responses required on the USB and move
the packet data through the dual port RAM to the DMA controller.
The Interval Timers provide timing strobes that identify important bus timing events: the bus
timeout interval, the microframe interval, the start of frame interval, and the bus reset, resume,
and suspend intervals.
Reports all transfer status to the DMA engine.
15.2.4 Port Controller
The port transceiver controller provides a couple of basic functions:
Suspend/Resume
For device mode, Chirp control.
15.2.5 ULPI Link Wrapper
The ULPI Link wrapper passes-through packet data and interprets Rx commands as well as send Tx
commands and provide viewport services to the software.
The ULPI link wrapper interfaces between the port controller (a bus similar to UTMI+ that connects
to the rest of the controller and its registers) and the ULPI interface.