EP80579 Datasheet, PDF (1033/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
Figure 26-1. USB Port Connections
cHC #2
(D29:F1)
cHC #1
(D29:F0)
Port 4
Port 3
Port 2
Port 1
Debug
Port
Enhanced Host Controller
Logic
26.11.1
Note:
26.11.2
Port-Routing Logic
Integrated into the EHC functionality is “port-routing logic,” which performs the muxing
between the classic and enhanced Host Controllers. CMI conceptually implements this
logic as described in the EHCI Specification, Rev. 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 cHC 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 HC that is not the owner of the port internally
sees a disconnected port.
The port-routing logic is the only block of logic that observes the physical (real)
connect/disconnect information. The port status logic inside each of the host controllers
observes the electrical (artificial) connect/disconnect information that is generated by
the port-routing logic.
Only the differential signal pairs are muxed/demuxed between the classic and
enhanced host controllers. The other USB functional signals are handled as follows:
• The Overcurrent inputs (OC#[3:0]) are directly routed to both controllers. An
overcurrent event is recorded in both controllers’ status registers.
• The Port Routing logic is implemented in the Suspend power well so that
reenumeration and remapping of the USB ports is not required following entering
and exiting a system sleep state in which the core power is turned off.
• CMI 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.
Device Connects
The EHCI Specification, Rev. 1.0 describes the details of handling Device Connects.
There are four general scenarios that are summarized below.
August 2009
Order Number: 320066-003US
Intel^® EP80579 Integrated Processor Product Line Datasheet
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