FW82801EB Intel, FW82801EB Datasheet - Page 223

• Manufacturer Part Number: FW82801EB
• Manufacturer: Intel

Specifications of FW82801EB

• Lead Free Status / RoHS Status: Not Compliant

5.20.8.1
Intel
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Figure 24. Intel
82801EB ICH5 / 82801ER ICH5R Datasheet
Port-Routing Logic
Integrated into the EHC functionality is port-routing logic, which performs the muxing between the
UHCI and EHCI host controllers. The ICH5 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.
Note that the port-routing logic is the only block of logic within the ICH5 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 muxed/demuxed between the UHCI and EHCI host
controllers. The other USB functional signals are handled as follows:
The Port-Routing logic is implemented in the Suspend power well so that re-enumeration and
re-mapping of the USB ports is not required following entering and exiting a system sleep state in
which the core power is turned off.
The ICH5 also allows the USB Debug Port traffic to be routed in and out of Port #0. When in this
mode, the Enhanced Host controller is the owner of Port #0.
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The Overcurrent inputs (OC[7:0]#) are directly routed to both controllers. An overcurrent
event is recorded in both controllers’ status registers.
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ICH5-USB Port Connections
Port 7
Port 6
Port 5
Port 4
Port 3
Port 2
Port 1
Port 0
Debug
Port
(D29:F3)
UHCI #4
Enhanced Host Controller Logic
(D29:F2)
UHCI #3
(D29:F1)
UHCI #2
Functional Description
UCHI #1
(D29:F0)
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