Cirrus Logic EP93xx - Manual (Page 474)

11-34 DS785UM1
Copyright 2007 Cirrus Logic
Universal Serial Bus Host Controller
EP93xx User’s Guide
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POCI: (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.
PRS: (READ) PortResetStatus. When this bit is set by a write to
SetPortReset, port reset signaling is asserted. When reset
is completed, this bit is cleared when
PortResetStatusChange is set. This bit cannot be set if
CurrentConnectStatus is cleared.
0 = port reset signal is not active
1 = port reset signal is active
(WRITE) SetPortReset. The HCD sets the port reset
signaling by writing a “1” to this bit. Writing a “0” has no
effect. If CurrentConnectStatus is cleared, this write does
not set PortResetStatus, but instead sets
ConnectStatusChange. This informs the driver that it
attempted to reset a disconnected port.
PPS: (READ) PortPowerStatus. 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 SetPortPower or
SetGlobalPower. HCD clears this bit by writing
ClearPortPower or ClearGlobalPower. Which power
control switches are enabled is determined by
PowerSwitchingMode and PortPortControlMask[NDP].
In global switching mode (PowerSwitchingMode=0), only
Set/ClearGlobalPower controls this bit. In per-port power
switching (PowerSwitchingMode=1), if the
PortPowerControlMask[NDP] bit for the port is set, only
Set/ClearPortPower commands are enabled. If the mask
is not set, only Set/ClearGlobalPower commands are
enabled. When port power is disabled,
CurrentConnectStatus, PortEnableStatus,
PortSuspendStatus, and PortResetStatus should be reset.
0 = port power is off
1 = port power is on