Specifications

Getting Started with FX2LP™
www.cypress.com Document No. 001-65209 Rev. *B 2
USB 2.0 Overview
Signaling rates supported by USB 2.0:
The USB 2.0 transfers signal and power over a four wire
cable and the supported data rates are:

The USB high-speed signaling bit rate is 480 Mbps.

The USB full-speed signaling bit rate is 12 Mbps.

The USB low-speed signaling bit rate is 1.5 Mbps.
NOTE: FX2LP does not support the low-speed signaling
mode of 1.5 Mbps.
If you are looking for a signaling rate more than 480 Mbps
on the USB bus then you should go for USB 3.0.
Cables and Connectors:
USB cable consists of four conductors, two power
conductors, and two signal conductors. High-/full-speed
cable consists of a signaling twisted pair, VBUS, GND,
and an overall shield. Table 1 shows the description of
these lines.
Table 1. USB 2.0 Pin Description
Pins Name Description Color
VBUS Power Red
D+
Differential pair
Green
D- White
GND Ground for power return Black
Figure 1 shows the cross section of the USB 2.0 cable.
Figure 1. USB 2.0 Cable Cross Section
Series “A” connector is used to connect the upstream
towards the host and Series “B” connector is used to
connect the downstream towards the devices. Standard
Series “B” connector is defined for relatively large and
stationary devices like hard drives, printers. Micro A-type
and B-type connectors are defined for handheld devices.
Protocol Layer:
USB 2.0 transaction consists of three packets: Token,
Data, and Handshake. Transaction is initiated with the
token packet and it is always from the host. Data packets
deliver the payload data and it can be sourced by the host
or device. Handshake packet acknowledges the error-free
receipt of data and it is being sent by the receiver of data.
USB transfer may consist of one or more transactions and
may spread across multiple frames. There are four types
of transfers defined by the USB Specification:

Control

Interrupt

Bulk

Isochronous
For more details on USB, visit www.usb.org/developers/docs/