Functional Description
5.19.8.1
Port-Routing Logic
Integrated into the EHC functionality is port-routing logic, which performs the muxing
between the UHCI and EHCI host controllers. The ICH10 conceptually implements this
logic as described in Section 4.2 of the Enhanced Host Controller Interface Specification
for Universal Serial Bus, Revision 1.0. If a device is connected that is not capable of
USB 2.0’s high-speed signaling protocol or if the EHCI software drivers are not present
as indicated by the Configured Flag, then the UHCI controller owns the port. Owning
the port means that the differential output is driven by the owner and the input stream
is only visible to the owner. The host controller that is not the owner of the port
internally sees a disconnected port.
Figure 5-14. Intel® ICH10-USB Port Connections Default Six and Six Configuration
EHCI #1
EHCI #2
UHCI
UHCI
UHCI
UHCI
UHCI
UHCI
UHCI
UHCI
Port 0
Port 1
Port 2
Port 3
Port 4
Port 5
Port 6
Port 7
Port 8
Port 9
Port 10
Port 11
Figure 5-15. Intel® ICH10-USB Port Connections Eight and Four Configuration
EHCI #1
EHCI #2
UHCI
UHCI
UHCI
UHCI
UHCI
UHCI
UHCI
UHCI
Port 0
Port 1
Port 2
Port 3 Port 4
Port 5
Port 10
Port 11
Port 6
Port 7
Port 8
Port 9
Note that the port-routing logic is the only block of logic within the ICH10 that observes
the physical (real) connect/disconnect information. The port status logic inside each of
the host controllers observes the electrical connect/disconnect information that is
generated by the port-routing logic.
Only the differential signal pairs are multiplexed/de-multiplexed between the UHCI and
EHCI host controllers. The other USB functional signals are handled as follows:
• The Overcurrent inputs (OC[11:0]#) are directly routed to both controllers. An
overcurrent event is recorded in both controllers’ status registers.
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Datasheet
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