AMD SB600 Technical Reference Manual page 55

Field Name Bits
CLF 1
BLF 2
OCR 3
Reserved 15:4
SOC 17:16
Reserved 31:18
©2008 Advanced Micro Devices, Inc.
AMD SB600 Register Reference Manual
HcCommandStatus - 32 bits - [MEM_Reg : 08h]
Default HCD HC
0b RW RW
0b RW RW
0b RW RW
00b R RW
Description
ControlListFilled
This bit is used to indicate whether there are any TDs
on the Control list. It is set by HCD whenever it adds
a TD to an ED in the Control list. When HC begins to
process the head of the Control list, it checks CLF. As
long as ControlListFilled is 0, HC will not start
processing the Control list. If CF is 1, HC will start
processing the Control list and will set
ControlListFilled to 0. If HC finds a TD on the list,
then HC will set ControlListFilled to 1 causing
the Control list processing to continue. If no TD is
found on the Control list, and if the HCD does not set
ControlListFilled, then ControlListFilled will still be 0
when HC completes processing the Control list and
Control list processing will stop.
BulkListFilled
This bit is used to indicate whether there are any TDs
on the Bulk list. It is set by HCD whenever it adds a
TD to an ED in the Bulk list. When HC begins to
process the head of the Bulk list, it checks BF. As
long as BulkListFilled is 0, HC will not start
processing the Bulk list. If BulkListFilled is 1, HC will
start processing the Bulk list and will set BF to 0. If
HC finds a TD on the list, then HC will set
BulkListFilled to 1 causing the Bulk list processing to
continue. If no TD is found on the Bulk list, and if
HCD does not set BulkListFilled, then BulkListFilled
will still be 0 when HC completes processing the Bulk
list and Bulk list processing will stop. BulkListFilled
This bit is used to indicate whether there are any TDs
on the Bulk list. It is set by HCD whenever it adds a
TD to an ED in the Bulk list. When HC begins to
process the head of the Bulk list, it checks BF. As
long as BulkListFilled is 0, HC will not start
processing the Bulk list. If BulkListFilled is 1, HC will
start processing the
Bulk list and will set BF to 0. If HC finds a TD on the
list, then HC will set BulkListFilled to 1 causing the
Bulk list processing to continue. If no TD is found on
the Bulk list, and if HCD does not set BulkListFilled,
then BulkListFilled will still be 0 when HC completes
processing the Bulk list and Bulk list processing will
stop.
OwnershipChangeRequest
This bit is set by an OS HCD to request a change of
control of the HC. When set HC will set the
OwnershipChange field in HcInterruptStatus. After
the changeover, this bit is cleared and remains so
until the next request from OS HCD.
SchedulingOverrunCount
These bits are incremented on each scheduling
overrun error. It is initialized to 00b and wraps around
at 11b. This will be incremented when a scheduling
overrun is detected even if SchedulingOverrun in
HcInterruptStatus has already been set. This is used
by HCD to monitor any persistent scheduling
problems.
Reserved
OCHI USB 1.1 and EHCI USB 2.0 Controllers
Proprietary Page 55