NH82801DB S L8DE Intel, NH82801DB S L8DE Datasheet - Page 204

• Manufacturer Part Number: NH82801DB S L8DE
• Manufacturer: Intel

Specifications of NH82801DB S L8DE

• Lead Free Status / RoHS Status: Compliant

Functional Description
5.17.8.3
5.17.8.4
5.17.9
204
Effect of Resets on Port-Routing Logic
Device Disconnects
Section 4.2 of the Enhanced Host Controller Interface (EHCI) for Universal Serial Bus
Specification describes the details of handling Device Connects. There are three general scenarios
that are summarized below.
As mentioned above, 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.
USB 2.0 Legacy Keyboard Operation
The ICH4 must support the possibility of a keyboard downstream from either a USB UHCI or a
USB EHCI port. The description of the legacy keyboard support is unchanged from USB UHCI
(See
The EHC provides the basic ability to generate SMIs on an interrupt event, along with more
sophisticated control of the generation of SMIs.
Suspend Well Reset
Core Well Reset
D3-to-D0 Reset
HCRESET
1. Configure Flag = 0 and the device is disconnected
2. Configure Flag = 1 and a USB Full-speed/Low-speed-capable Device is disconnected
3. Configure Flag = 1 and a USB High-speed-capable Device is disconnected
Section
— In this case, the USB UHCI controller is the owner of the port both before and after the
— In this case, the USB UHCI controller is the owner of the port before the disconnect
— In this case, the USB EHCI controller is the owner of the port before, and remains the
disconnect occurs. The EHC (except for the port-routing logic) never sees a device
attached. The UHCI driver handles disconnection process.
occurs. The disconnect is reported by the USB UHCI controller and serviced by the
associated UHCI driver. The port-routing logic in the EHC cluster forces the Port Owner
bit to 0, indicating that the EHC owns the unconnected port.
owner after, the disconnect occurs. The EHCI hardware and driver handle the
disconnection process. The USB UHCI controller never sees a device attached.
Reset Event
5.16.8).
Effect on Configure Flag
cleared (0)
cleared (0)
no effect
no effect
Intel
Effect on Port Owner Bits
®
82801DB ICH4 Datasheet
no effect
no effect
set (1)
set (1)