FW82801EB Intel, FW82801EB Datasheet - Page 478

• Manufacturer Part Number: FW82801EB
• Manufacturer: Intel

Specifications of FW82801EB

• Lead Free Status / RoHS Status: Not Compliant

UHCI Controllers Registers
478
5:4
Bit
3
2
1
0
Line Status — RO. These bits reflect the D+ (bit 4) and D– (bit 5) signals lines’ logical levels. These
bits are used for fault detect and recovery as well as for USB diagnostics. This field is updated at
EOF2 time (See Chapter 11 of the Universal Serial Bus Revision 2.0 Specification).
Port Enable/Disable Change — R/WC. For the root hub, this bit gets set only when a port is
disabled due to disconnect on that port or due to the appropriate conditions existing at the EOF2
point (See Chapter 11 of the Universal Serial Bus Revision 2.0 Specification).
0 = No change. Software clears this bit by writing a 1 to the bit location.
1 = Port enabled/disabled status has changed.
Port Enabled/Disabled (PORT_EN) — R/W. Ports can be enabled by host software only. Ports can
be disabled by either a fault condition (disconnect event or other fault condition) or by host software.
Note that the bit status does not change until the port state actually changes and that there may be
a delay in disabling or enabling a port if there is a transaction currently in progress on the USB.
0 = Disable
1 = Enable
Connect Status Change — R/WC. This bit indicates that a change has occurred in the port’s
Current Connect Status (see bit 0). The hub device sets this bit for any changes to the port device
connect status, even if system software has not cleared a connect status change. If, for example,
the insertion status changes twice before system software has cleared the changed condition, hub
hardware will be setting” an already-set bit (i.e., the bit will remain set). However, the hub transfers
the change bit only once when the host controller requests a data transfer to the Status Change
endpoint. System software is responsible for determining state change history in such a case.
0 = No change. Software clears this bit by writing a 1 to it.
1 = Change in Current Connect Status.
Current Connect Status — RO. This value reflects the current state of the port, and may not
correspond directly to the event that caused the Connect Status Change bit (Bit 1) to be set.
0 = No device is present.
1 = Device is present on port.
Intel
Description
®
82801EB ICH5 / 82801ER ICH5R Datasheet