Allwinner A20 - Page 692

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16
R/W
R
0x0
The Root Hub does not support the local power status features,
thus, this bit is always read as ‘0’.
(write)SetGlobalPower
In global power mode (PowerSwitchingMode=0), This bit is
written to ‘1’ to turn on power to all ports (clear PortPowerStatus).
In per-port power mode, it sets PortPowerStatus only on ports
whose PortPowerControlMask bit is not set. Writing a ‘0’ has no
effect.
15
R/W
R
0x0
(read)DeviceRemoteWakeupEnable
This bit enables a ConnectStatusChange bit as a resume event,
causing a USBSUSPEND to USBRESUME state transition and
setting the ResumeDetected interrupt.
0
ConnectStatusChange is not a remote wakeup event.
1
ConnectStatusChange is a remote wakeup event.
(write)SetRemoteWakeupEnable
Writing a ‘1’ sets DeviceRemoveWakeupEnable. Writing a ‘0’ has
no effect.
14:2
/
/
/
Reserved
1
R
R/W
0x0
OverCurrentIndicator
This bit reports overcurrent conditions when the global reporting is
implemented. When set, an overcurrent condition exists. When
cleared, all power operations are normal.
If per-port overcurrent protection is implemented this bit is always
‘0’
0
R/W
R
0x0
(Read)LocalPowerStatus
When read, this bit returns the LocalPowerStatus of the Root Hub.
The Root Hub does not support the local power status feature;
thus, this bit is always read as ‘0’.
(Write)ClearGlobalPower
When write, this bit is operated as the ClearGlobalPower. In global
power mode (PowerSwitchingMode=0), This bit is written to ‘1’ to
turn off power to all ports (clear PortPowerStatus). In per-port
power mode, it clears PortPowerStatus only on ports whose
PortPowerControlMask bit is not set. Writing a ‘0’ has no effect.
6.8.7.22. HCRHPORTSTATUS REGISTER
Offset: 0x454
Register Name: HcRhPortStatus
Default Value:0x100
Bit
Read/Write
Default
Description
HCD
HC
31:21
-
Reserved
20
R/W
R/W
0x0
PortResetStatusChange
This bit is set at the end of the 10-ms port reset signal. The HCD
writes a ‘1’ to clear this bit. Writing a ‘0’ has no effect.
0
port reset is not complete
1
port reset is complete
PortOverCurrentIndicatorChange
This bit is valid only if overcurrent conditions are reported on a