RM0082
HS_USB2.0 host
Doc ID 018672 Rev 1
457/844
Table 385.
HcRhDescriptorB register bit assignments
22.6.48 HcRhStatus
register
The HcRhStatus register is divided into two parts. The lower word of a Dword represents the
Hub Status field and the upper word represents the Hub Status Change field. Reserved bits
should always be written '0'.
Bits
Name
Reset
Read/Write
Description
HCD
HC
[31:16]
PPCM
IS
R/W
R
PortPowerControlMask
Each bit indicates if a port is affected by a global power
control command when PowerSwitchingMode is set.
When set, the port's power state is only affected by per-
port power control (Set/ClearPortPower). When cleared,
the port is controlled by the global power switch
(Set/ClearGlobalPower). If the device is configured to
global switching mode
(PowerSwitchingMode=0), this field is not valid.
bit 0: Reserved
bit 1: Ganged-power mask on Port #1
bit 2: Ganged-power mask on Port #2
...
bit15: Ganged-power mask on Port #15
[15:00]
DR
IS
R/W
R
DeviceRemovable
Each bit is dedicated to a port of the Root Hub. When
cleared, the attached device is removable. When set, the
attached device is not removable.
bit 0: Reserved
bit 1: Device attached to Port #1
bit 2: Device attached to Port #2
...
bit15: Device attached to Port #15
Table 386.
HcRhStatus register bit assignments
Bits
Name
Reset
Read/Write
Description
HCD
HC
[31]
CRWE
W
R
(write) ClearRemoteWakeupEnable
Writing a '1' clears DeviceRemoveWakeupEnable. Writing
a '0' has no effect.
[30:18]
Reserved
[17]
OCIC
0b
R/W
R/W
OverCurrentIndicatorChange
This bit is set by hardware when a change has occurred to
the OCI field of this register. The HCD clears this bit by
writing a ‘1’. Writing a ‘0’ has no effect.