NO:
W90P710 Programming Guide
VERSION:
2.1
PAGE:
81
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
Once the
Host Controller
has accomplished the processing of a
TD
, in spite of success or failure,
Host Controller
will remove the
TD
from
TD
queue and put it into the
Done Queue
.
Host Controller
will
follow the following steps to remove a
TD
:
1. Modify the
HeadP
pointer of the
Endpoint Descriptor
(HC always service the first
TD
of the
TD
queue) to link to the next
TD
, HC can obtain the link of the next
TD
by reading the
NextTD
pointer of the first
TD
2. Now the
TD
has been unlinked from
TD
queue, HC moves the
TD
to the head of
Done
Queue
, which is pointed by
HcDoneHead
register
3. HC moves the retired
TD
to the
Done Queue
by writing the contains of
HcDoneHead
to the
NextTD
field of the retired
TD
, and then have the
HcDoneHead
point to the retired
TD
In some situation, the client software may cancel an
IRP
before the
IRP
was completed. This