AMD SB600 - Manual (Page 64)

©2008 Advanced Micro Devices, Inc. OCHI USB 1.1 and EHCI USB 2.0 Controllers
AMD SB600 Register Reference Manual Proprietary Page 64
HcRhPortStatus - 32 bits - [MEM_Reg : 50h+4*(1:NDP)]
Field Name Bits Default HCD HC Description
PES 1 0b RW RW (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
ClearPortEnabl
e. 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.
PSS 2 0b RW RW (Read) PortSuspendStatus
This bit indicates the port is suspended or in the
resume sequence. It is set by a SetSuspendState
write and cleared when PortSuspendStatusChange
is set at the end of the resume interval. This bit
cannot be set if CurrentConnectStatus is cleared.
This bit is also cleared when
PortResetStatusChange
is set at the end of the port
reset or when the HC is placed in the USBRESUME
state. If an upstream resume is in progress, it should
propagate to the HC.
0 = Port is not suspended
1 = Port is suspended
(Write) SetPortSuspend
The HCD sets the PortSuspendStatus bit by writing
a ‘1’ to this bit. Writing a ‘0’ has no effect. If
CurrentConnectStatus
is cleared, this write does
not set PortSuspendStatus; instead it sets
ConnectStatusChang
e. This informs the driver that
it attempted to suspend a disconnected port.
POCI 3 0b RW RW (Read) PortOverCurrentIndicator
This bit is only valid when the Root Hub is configured
in such a way that overcurrent conditions are
reported on a per-port basis. If per-port overcurrent
reporting is not supported, this bit is set to 0. If
cleared, all power operations are normal for this port.
If set, an overcurrent condition exists on this port.
This bit always reflects the overcurrent input signal
0 = No overcurrent condition.
1 = Overcurrent condition detected.
(Write) ClearSuspendStatus
The HCD writes a ‘1’ to initiate a resume. Writing a ‘0’
has no effect. A resume is initiated only if
PortSuspendStatus
is set.