Publication No. SBC329-HRM/1
Functional Description 59
5.10 USB
The PCH provides up to three USB ports using XHCI controllers. These ports are
called USB_P0, USB_P1 and USB_P2 from here on. USB_P0 and USB_P1 are always
available; USB_P2 is available as a build option and its backplane connections are
shared with XMC user I/O (see the
section). USB_P0 and USB_P1 are
USB2.0 (high speed) capable, and USB_P2 (when available) is USB3.0 (Super Speed)
capable.
NOTE
Due to limitations in the VPX backplane bandwidth capability, the use of signal re-drivers at the
system level may be required to guarantee USB3.0 Super speed operation. The RTMs for the
SBC329 (VPX3UX301 and VPX3UX601) include re-drivers on USB_P2 signals.
Two power switches are used to switch VBUS power to the ports. USB_P0 and
USB_P1 share a single backplane pin for VBUS power (maximum 1A for both ports).
USB_P2 has its own VBUS power pin (maximum 1A for this port). The power
switches provide over-current protection (OCP) and can signal over-current
conditions to the PCH.
NOTE
The PCH does not support OCP for each port independently, and OCP inputs are shared across
ports.
The following tables show where each USB port is connected (assuming the board is
configured accordingly).
For USB2.0 operation:
Table 5-8 USB Signal Availability
Port PCH Port number USB_Px_P USB_Px_N USB_Px_PWR
0
0
P1/E10
P1/F10
P2/G11
1
1
P2/G15
P2/G13
P2/G11
2
8
P2/A3
P2/B3
P2/D3 and P2/E3
For USB_P2 in USB3.0 operation:
USB_P2_RXP USB_P2_RXN USB_P2_TXP USB_P2_TXN USB_P2_PWRA USB_P2_PWRB
P2/B4
P2/C4
P2/E4
P2/F4
P2/D3
P2/E3