ISP1160
Embedded USB Host Controller
Philips Semiconductors
Table 35: HcRshPortStatus[1:2] register: bit description…continued
Bit
Symbol
Description
8
PPS
On read—PortPowerStatus: This bit reflects the port power
status, regardless of the type of power switching implemented.
This bit is cleared if an overcurrent condition is detected.
The HCD sets this bit by writing SetPortPower or SetGlobalPower.
The HCD clears this bit by writing ClearPortPower or
ClearGlobalPower. Which power control switches are enabled is
determined by PowerSwitchingMode.
In the global switching mode (PowerSwitchingMode = 0), only
Set/ClearGlobalPower controls this bit. In per-port power switching
(PowerSwitchingMode = 1), if bit PortPowerControlMask[NDP] 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
On write—SetPortPower: The HCD writes a logic 1 to set
bit PortPowerStatus. Writing a logic 0 has no effect.
Remark: This bit always reads logic 1 if power switching is not
supported.
7 to 5
4
-
reserved
PRS
On 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
On write—SetPortReset: The HCD sets the port reset signaling
by writing a logic 1 to this bit. Writing a logic 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.
3
POCI
On read—PortOverCurrentIndicator: This bit is valid only 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 logic 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 logic 1 to initiate
a resume. Writing a logic 0 has no effect. A resume is initiated only
if PortSuspendStatus is set.
9397 750 11371
© Koninklijke Philips Electronics N.V. 2003. All rights reserved.
Product data
Rev. 04 — 04 July 2003
55 of 88
NXP [ NXP ]
