Owners manual

Interfaces
H3 Datasheet(Revision1.2) Copyright© 2015 Allwinner Technology Co.,Ltd.All Rights Reserved. Page 503
The default value of this bit is ‘0’.
3
R/WC
0
Port Enable/Disable Change
Default = 0. 1 = Port enabled/disabled status has changed. 0 = No change.
For the root hub, this bit gets set to a one only when a port is disabled due
to the appropriate conditions existing at the EOF2 point (See Chapter 11 of
the USB Specification for the definition of a Port Error). Software clears this
bit by writing a 1 to it.
This field is zero if Port Power is zero.
2
R/W
0
Port Enabled/Disabled
1=Enable, 0=Disable. Ports can only be enabled by the host controller as a
part of the reset and enable. Software cannot enable a port by writing a one
to this field. The host controller will only set this bit to a one when the reset
sequence determines that the attached device is a high-speed device.
Ports can be disabled by either a fault condition(disconnect event or other
fault condition) or by host software. Note that the bit status does not
change until the port state actually changes. There may be a delay in
disabling or enabling a port due to other host controller and bus events.
When the port is disabled, downstream propagation of data is blocked on
this port except for reset.
The default value of this field is ‘0’.
This field is zero if Port Power is zero.
1
R/WC
0
Connect Status Change
1=Change in Current Connect Status, 0=No change, Default=0.
Indicates a change has occurred in the port’s Current Connect Status. The
host controller sets this bit for all changes to the port device connect status,
even if system software has not cleared an existing connect status change.
For example, the insertion status changes twice before system software has
cleared the changed condition, hub hardware will be “setting” an
already-set bit. Software sets this bit to 0 by writing a 1 to it.
This field is zero if Port Power is zero.
0
R
0
Current Connect Status
Device is present on port when the value of this field is a one, and no device
is present on port when the value of this field is a zero. This value reflects
the current state of the port, and may not correspond directly to the event
that caused the Connect Status Change(Bit 1) to be set.
This field is zero if Port Power zero.
Note: This register is only reset by hardware or in response to a host controller reset.
8.5.2.6. OHCI Register Description
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