HS_USB2.0 host
RM0082
462/844
Doc ID 018672 Rev 1
[01]
PES
0b
R/W
R/W
(read) PortEnableStatus
This bit indicates whether the port is enabled or disabled.
The Root Hub may clear this bit when an overcurrent
condition, disconnect event, switched-off power, or
operational bus error such as babble is detected. This
change also causes PortEnabledStatusChange to be set.
HCD sets this bit by writing SetPortEnable and clears it by
writing ClearPortEnable. This bit cannot be set when
CurrentConnectStatus is cleared. This bit is also set, if not
already, at the completion of a port reset when
ResetStatusChange is set or port suspend when
SuspendStatusChange is set.
0 = port is disabled
1 = port is enabled
(write) SetPortEnable
The HCD sets PortEnableStatus by writing a ‘1’. Writing a
‘0’ has no effect. If CurrentConnectStatus is cleared, this
write does not set PortEnableStatus, but instead sets
ConnectStatusChange. This informs the driver that it
attempted to enable a disconnected port.
[00]
CCS
0b
R/W
R/W
(read) CurrentConnectStatus
This bit reflects the current state of the downstream port.
0 = no device connected
1 = device connected
(write) ClearPortEnable
The HCD writes a ‘1’ to this bit to clear the
PortEnableStatus bit. Writing a ‘0’ has no effect. The
CurrentConnectStatus is not affected by any write.
Note: This bit is always read ‘1b’ when the attached
device is nonremovable (DeviceRemoveable[NDP]).
Table 387.
HcRhPortStatus register bit assignments (continued)
Bits
Name
Reset
Read/write
Description
HCD
HC