82801CA Datasheet, PDF (183/521 Pages) Intel Corporation – I/O Controller Hub 3-S (ICH3-S)

Functional Description
QH
QHLP
QT
QE QELP Vf Q T
TDLP
TD
Vf Q T
Legend:
QH.LP = Queue Head Link Pointer (or Horizontal Link Pointer)
QE.LP = Queue Element Link Pointer (or Vertical Link Pointer)
TD.LP = TD Link Pointer
QH.Q = Q bit in QH
QH.T = T bit in QH
Table 5-67. USB Schedule List Traversal Decision Table
QE.Q = Q bit in QE
QE.T = T bit in QE
TD. Vf = Vf bit in TD
TD.Q = Q bit in TD
TD. T = T bit in TD
Q
Context
QH.Q
0
-
0
-
0
-
1
0
1
x
1
x
1
0
1
x
1
x
1
x
1
1
1
1
QH.T
-
-
-
0
x
x
0
x
1
1
0
0
QE.Q
-
-
-
0
0
0
x
1
0
x
0
x
QE.T
-
-
-
0
0
0
1
0
0
1
0
1
TD.Vf
x
x
x
0
1
1
x
-
0
x
0
x
TD.Q
0
x
1
x
0
1
x
-
x
x
x
x
TD.T
Description
Not in Queue–execute TD.
0
Use TD.LP to get next TD
1 Not in Queue–execute TD. End of Frame
Not in Queue –execute TD.
0 Use TD.LP to get next (QH+QE).
Set Q Context to 1.
In Queue. Use QE.LP to get TD.
x Execute TD. Update QE.LP with TD.LP.
Use QH.LP to get next TD.
In Queue. Use QE.LP to get TD.
0 Execute TD. Update QE.LP with TD.LP.
Use TD.LP to get next TD.
In Queue. Use QE.LP to get TD.
0 Execute TD. Update QE.LP with TD.LP.
Use TD.LP to get next (QH+QE).
In Queue. Empty queue.
x
Use QH.LP to get next TD
- In Queue. Use QE.LP to get (QH+QE)
In Queue. Use QE.LP to get TD.
x Execute TD. Update QE.LP with TD.LP.
End of Frame
x In Queue. Empty queue. End of Frame
In Queue. Use QE.LP to get TD.
x Execute TD. Update QE.LP with TD.LP.
Use QH.LP to get next (QH+QE).
In Queue. Empty queue.
x
Use QH.LP to get next (QH+QE)
Intel^® 82801CA ICH3-S Datasheet
183