Freescale Semiconductor TWR-MCF52259-Ethenet, Руководство пользователя, Страница: 127 / 166

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.