Functional Description
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 ICH10 also allows the USB Debug Port traffic to be routed in and out of Port #0 and
Port #6. When in this mode, the Enhanced Host controller is the owner of Port #0 and
Port #6.
5.19.8.2
Device Connects
The Enhanced Host Controller Interface Specification for Universal Serial Bus, Revision
1.0 describes the details of handling Device Connects in Section 4.2. There are four
general scenarios that are summarized below.
1. Configure Flag = 0 and a full-speed/low-speed-only Device is connected
— In this case, the UHC is the owner of the port both before and after the connect
occurs. The EHC (except for the port-routing logic) never sees the connect
occur. The UHCI driver handles the connection and initialization process.
2. Configure Flag = 0 and a high-speed-capable Device is connected
— In this case, the UHC is the owner of the port both before and after the connect
occurs. The EHC (except for the port-routing logic) never sees the connect
occur. The UHCI driver handles the connection and initialization process. Since
the UHC does not perform the high-speed chirp handshake, the device operates
in compatible mode.
3. Configure Flag = 1 and a full-speed/low-speed-only Device is connected
— In this case, the EHC is the owner of the port before the connect occurs. The
EHCI driver handles the connection and performs the port reset. After the reset
process completes, the EHC hardware has cleared (not set) the Port Enable bit
in the EHC’s PORTSC register. The EHCI driver then writes a 1 to the Port Owner
bit in the same register, causing the UHC to see a connect event and the EHC to
see an “electrical” disconnect event. The UHCI driver and hardware handle the
connection and initialization process from that point on. The EHCI driver and
hardware handle the perceived disconnect.
4. Configure Flag = 1 and a high-speed-capable Device is connected
— In this case, the EHC is the owner of the port before, and remains the owner
after, the connect occurs. The EHCI driver handles the connection and performs
the port reset. After the reset process completes, the EHC hardware has set the
Port Enable bit in the EHC’s PORTSC register. The port is functional at this point.
The UHC continues to see an unconnected port.
Datasheet
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INTEL [ INTEL ]
