SIS5595 Datasheet, PDF (198/216 Pages) List of Unclassifed Manufacturers – Pentium PCI System I/O Chipset

SiS5595 PCI System I/O Chipset
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15:10
9
8
7:5
R/W ConnectStatusChange
This bit is set whenever a connect or disconnect event occurs.
The HCD writes a '1' to clear this bit. Writing a ‘0’ has no effect.
If CurrentConnectStatus is cleared when a SetPortReset,
SetPortEnable, or SetPortSuspend write occurs, this bit is set to
force the driver to re-evaluate the connection status since these
writes should not occur if the port is disconnected.
0 : no change in CurrentConnectStatus
1 : change in CurrentConnectStatus
Note: If the DeviceRemovable[NDP] bit is set, this bit is set only
after a Root Hub reset to inform the system that the device is
attached.
Reserved
R/W LowSpeedDeviceAttached((Read))
This bit indicates the speed of the device attached to this port.
When set, a Low Speed device is attached to this port. When
clear, a Full Speed device is attached to this port. This field is
valid only when the CurrentConnectStatus is set.
0 : full speed device attached
1 : low speed device attached
R/W Port Power Status((Read))
This bit reflects the port’s power status, regardless of the type of
power switching implemented. This bit is cleared if an
overcurrent condition is detected. HCD sets this bit by writing Set
Port Power or Set Global Power. HCD clears this bit by writing
Clear Port Power or Clear Global Power. Which power control
switches are enabled is determined by Power Switching Mode
and Port Port Control Mask[NDP]. In global switching mode
(Power Switching Mode=0), only Set/ClearGlobalPower controls
this bit. In per-port power switching (Power Switching Mode=1), if
the Port Power Control Mask[NDP] bit for the port is set, only
Set/ClearPortPower commands are enabled. If the mask is not
set, only Set/ Clear Global Power commands are enabled. When
port power is disabled, Current Connect Status, Port Enable
Status, Port Suspend Status, and Port Reset Status should be
reset.
0 : port power is off
1 : port power is on
SetPortPower(Write)
The HCD writes a '1' to set the PortPowerStatus bit. Writing a
‘0’ has no effect.
Note: This bit is always reads ‘1b’ if power switching is not
supported.
Reserved
Preliminary V2.0 Nov. 2, 1998
192 Silicon Integrated Systems Corporation