NO:
W90P710 Programming Guide
VERSION:
2.1
PAGE:
90
The above information is the exclusive intellectual property of Winbond Electronics and shall not be disclosed,
distributed or reproduced without permission from Winbond.
Table No.: 1200-0003-07-A
6.5.7.2
Processing Done Queue
Now that the
Done Queue
is inversed into its original order,
HCD
can start to process the
TD
s
one by one. For each
TD
,
HCD
checks whether the
TD
was completed with any errors. While
processing each
TD
, the
HCD
must determine whether an
IRP
was completed.
HCD
recorded the
TD
s linked to a specific
IRP
and would know whether all
TD
s belong to the same
IRP
had been
completed. In the example code, once all
TD
s of an
IRP
had been completed,
HCD
would invoke
sochi_return_urb( )
to reclaim the
IRP
.
In the
sochi_return_urb( )
routine,
HCD
would invoke the complete routine of the
IRP
. The
complete routine is a callback routine provided by
Client Software
or
USB Driver
and used to notify
the completion of an
IRP
. The
Client Software
or
USB Driver
may collect data received by
Host
Controller
or do nothing, it depends on the implementation. In addition to invoke complete routine,
HCD
may release the
IRP
or re-submit the
IRP
if it is the Interrupt Transfer type.
6.5.8 Root Hub
The
Root Hub
is integrated into
Host Controller
and the control of
Root Hub
is done by accessing
register files. W90P710
Host Controller
has provided several
Root Hub
related registers. The
HcRhDescriptorA
and
HcRhDescriptorB
registers are informative registers, which are used to
describe the characteristics and capabilities of
Root Hub
. The
HcRhStatus
register presents the
current status and reflects the change of status of
Root Hub
. The
HcRhPortStatus
register presents
the current status and reflects the change of status of a
Root Hub
port. W90P710
Root Hub
has two
hub ports, the
HcRhPortStatus[1]
and
HcRhPortStatus[2]
are respectively dedicated to port 0 and
port 1.
6.5.8.1
HcRhDescriptorA and HcRhDescriptorB
The
HcRhDescriptorA
and
HcRhDescriptorB
registers are informative registers, which are
used to describe the characteristics and capabilities of
Root Hub
. The characteristics and capabilities
of W90P710
Root Hub
are listed in the followings :
•
Two
downstream
ports