HS_USB2.0 host
RM0082
446/844
Doc ID 018672 Rev 1
Table 369.
HcInterruptStatus register bit assignments
Bits
Name
Reset
Read/Write
Description
HCD
HC
[31]
Reserved
[30]
OC
0b
R/W
R/W
OwnershipChange
This bit is set by HC when HCD sets the
OwnershipChangeRequest field in HcCommandStatus.
This event, when unmasked, will always generate an
System Management Interrupt (SMI) immediately.
This bit is tied to 0b when the SMI pin is not implemented.
[29:07]
Reserved
[06]
RHSC 0b
R/W/
R/W
RootHubStatusChange
This bit is set when the content of HcRhStatus or the
content of any of
HcRhPortStatus[NumberofDownstreamPort] has
changed.
[05]
FN0
0b
R/W
R/W
FrameNumberOverflow
This bit is set when the MSb of HcFmNumber (bit 15)
changes value, from 0 to 1 or from 1 to 0, and after
HccaFrameNumber has been updated.
[04]
UE
0b
R/W
R/W
UnrecoverableError
This bit is set when HC detects a system error not related
to USB. HC should not proceed with any processing nor
signaling before the system error has been corrected.
HCD clears this bit after HC has been reset.
[03]
RD
0b
R/W
R/W
ResumeDetected
This bit is set when HC detects that a device on the USB
is asserting resume signaling. It is the transition from no
resume signaling to resume signaling causing this bit to
be set. This bit is not set when HCD sets the
USBRESUME state.
[02]
SF
0b
R/W
R/W
StartofFrame
This bit is set by HC at each start of a frame and after the
update of HccaFrameNumber. HC also generates a SOF
token at the same time.
[01]
WDH
0b
R/W
R/W
WritebackDoneHead
This bit is set immediately after HC has written
HcDoneHead to HccaDoneHead. Further updates of the
HccaDoneHead will not occur until this bit has been
cleared. HCD should only clear this bit after it has saved
the content of HccaDoneHead.
[00]
SO
0b
R/W
R/W
SchedulingOverrun
This bit is set when the USB schedule for the current
Frame overruns and after the update of
HccaFrameNumber. A scheduling overrun will also cause
the SchedulingOverrunCount of HcCommandStatus to be
incremented.