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Usb on-the-go – Freescale Semiconductor TWR-MCF52259-Ethenet User Manual

Page 127

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TM

U

S

B

T

o

p

o

lo

g

y

Introduction to USB

USB On-the-Go:

Initial declaration

A

p

p

en

d

ix

A

U

S

B

O

n

-t

h

e-

G

o

D+

D-

V

BUS

GND

ID

Mini-A plug

Mini-B plug

Dual-role

Device

Dual-role

Device

Mini-AB receptacle

Default Host

Default Peripheral

A-device

B-device

D+

D-

V

BUS

GND

ID

When using A and B plugs, initially the device using the A plug is
declared the host and the one using the B plug is declared the
device. When using the mini-AB receptacle the ID plug pin declares
the initial state of a device as host or device. State is then changed
during host negotiations protocol by turning a pull-up resistor on
and off.