
REF: BB_SRM_xM
BeagleBoard-xM System
Reference Manual
Revision C2
Page 82 of 163
The LAN9514 requires an external 25MHZ crystal to generate the required internal
clocks. The optional 24MHz clock output is not used on the board and is disabled.
The AUTOMIDX feature is enabled which allows for auto polarity detection. This
enables the port to automatically switch the TX and RX leads if needed.
7.14.4
USB Port Connectors
There a two dual port type A USB connectors used on the –xM board each one provides
connections for four signals, DP, DM, VBUS, and Ground. You will notice that there are
no external ESD devices on the connector. The ESD protection is integrated into the USB
HUB.
Figure 41
is the design of the power control for each USB host port. Each port can be
turned on or off from the
LAN9514
over the USB interface. U13, a TPS2045, is a four
port FET with over current detection. The overcurrent detect output is tied to the enable
pin from the LAN9514. In an over current condition the signal is immediately turned off
without waiting for the processor to turn off the power. The
LAN9514
detects the
overcurrent condition and keeps the over current condition turned off.
VBUS3
VBUS4
SHIELD
SHIELD
VBUSA
DA-
DA+
GNDA
VBUSB
DB-
DB+
GNDB
SHIELD
SHIELD
P16
USB-A Conn.
A1
A3
A2
A4
MH1
MH2
B1
B2
B3
B4
MH3
MH4
VBUS1
+
C160
100UF
VBUS2
+
C161
100UF
U13
TPS2054BD
IN1
2
EN1
3
OUT1
15
OUT3
11
GN
D
1
IN2
6
OUT2
14
OC1
16
OUT4
10
GN
D
5
EN2
4
EN3
7
EN4
8
OC2
13
OC3
12
OC4
9
ES
D
_R
IN
G
VBUS3
+
C162
100UF
+
C163
100UF
VBUS4
SHIELD
SHIELD
VBUSA
DA-
DA+
GNDA
VBUSB
DB-
DB+
GNDB
SHIELD
SHIELD
P14
USB-A Conn.
A1
A3
A2
A4
MH1
MH2
B1
B2
B3
B4
MH3
MH4
USBDP_2
USBDM_2
USBDP_1
C
17
3
0.
1u
F
,10
V
DC_5V_USB
C
17
2
0.
1u
F
,10
V
C
17
1
0.
1u
F
,10
V
USBDP_3
USBDM_4
USBDM_3
USBDM_1
USBDP_4
C
17
0
0.
1u
F
,10
V
VBUS1
VBUS2
U15
LAN9514
USBDP2
2
USBDP3
4
USBDP4
7
USBDP5
9
USBDM2
1
USBDM3
3
USBDM4
6
USBDM5
8
PRTCTL2
14
PRTCTL3
16
PRTCTL4
17
PRTCTL5
18
Figure 40.
USB Port Power Design
Summary of Contents for XM C2
Page 152: ...REF BB_SRM_xM BeagleBoard xM System Reference Manual Revision C2 Page 152 of 163 ...
Page 153: ...REF BB_SRM_xM BeagleBoard xM System Reference Manual Revision C2 Page 153 of 163 ...
Page 154: ...REF BB_SRM_xM BeagleBoard xM System Reference Manual Revision C2 Page 154 of 163 ...
Page 155: ...REF BB_SRM_xM BeagleBoard xM System Reference Manual Revision C2 Page 155 of 163 ...
Page 156: ...REF BB_SRM_xM BeagleBoard xM System Reference Manual Revision C2 Page 156 of 163 ...
Page 157: ...REF BB_SRM_xM BeagleBoard xM System Reference Manual Revision C2 Page 157 of 163 ...
Page 158: ...REF BB_SRM_xM BeagleBoard xM System Reference Manual Revision C2 Page 158 of 163 ...
Page 159: ...REF BB_SRM_xM BeagleBoard xM System Reference Manual Revision C2 Page 159 of 163 ...
Page 160: ...REF BB_SRM_xM BeagleBoard xM System Reference Manual Revision C2 Page 160 of 163 ...
Page 161: ...REF BB_SRM_xM BeagleBoard xM System Reference Manual Revision C2 Page 161 of 163 ...