
CHAPTER 14 USBU (UNIVERSAL SERIAL BUS UNIT)
User’s Manual U14579EJ2V0UM
311
(2/2)
Bit
Name
Function
31
CRWE
Clean Remote Wakeup Enable
1: Clear the RWE bit of the HcControl register to 0.
0: No change
30:18
RFU
Reserved. Write 0 to these bits. Since the values of these bits are undefined after a
reset, initialize them by using software.
17
OCIC
Over Current Indicator Change
The HC sets 1 in this bit when a change occurs in the OCI bit. This bit is cleared to 0
when 1 is written by the HCD. It does not change when 0 is written by the HCD.
SGP
Note
<For HCD write>
Set Global Power
1: When the PSM bit of the HcRhDescriptorA register is 1, set (1) only the PPS bit of
the HcRhPortStatus register of the port that is not set in the PPCM area of the
HcRhDescriptorB register. When the PSM bit of the HcRhDescriptorA register is
0, turn on the port of all ports.
0: No change
16
LPSC
<For HCD read or HC read>
Local Power Status Change
The root hub does not support the local power status.
SRWE
Note
<For HCD write>
Set Remote Wakeup Enable
1: Set the RWE bit of the HcControl register
0: No change
15
DRWE
<For HCD read or HC read>
Device Remote Wakeup Enable
1: Indicates that the event is a remote wakeup event when the CSC bit of the
HcRhPortStatus register is 1.
0: Indicates that the event is not a remote wakeup event when the CSC bit of the
HcRhPortStatus register is 1.
14:2
RFU
Reserved. Write 0 to these bits. Since the values of these bits are undefined after a
reset, initialize them by using software.
1
OCI
Over Current Indicator
Existence of an over current state (when all downstream ports are reported in a
batch)
1: An over current state exists
0: Current is operating normally
When an over current state is reported for each port, clear this bit to 0.
CGP
Note
<For HCD write>
Clear Global Power
1: When the PSM bit of the HcRhDescriptorA register is 1, clear to 0 only the PPS
bit of the HcRhPortStatus register of the port that is not set in the PPCM area of
the HcRhDescriptorB register. When the PSM bit of the HcRhDescriptorA register
is 0, turn off the power supplies of all ports.
0: No change
0
LPS
<For HCD read or HC read>
Local Power Status
The root hub does not support the local power supply status.
Note These bits can be only written by the HCD. They cannot be read/written by the HC.