Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
271
Address Translation Unit (PCI Express)—Intel
®
81341 and 81342
3.8.3.1
Transaction Ordering Summary
and
, define transaction ordering in relation to token assignment of
the priority mechanism (see
). These tables are read as follows:
1. As transaction enters the respective queue head, the question in column 2 is asked.
2. When all the answers in column 3 for a given transaction type assigns a token to
the transaction at the head of the queue, a token is assigned. Otherwise, no token
is assigned signifying that transaction ordering must first be satisfied. Any
transaction with a token may be initiated on the bus.
Table 127. Inbound Transaction Ordering Summary
Transaction at Head of Queue
Question
Answer
Action
Inbound Posted Transaction Write
in IPHQ
Is there an Inbound Posted Request with
an earlier time stamp?
Yes
Do Not Assign Token
Allow previous Transaction to Complete
No
Assign Token
Inbound Non Posted Request in
INPHQ
Is there an Inbound Write with an earlier
time stamp?
Yes
Do Not Assign Token
Allow previous Transaction to Complete
No
Assign Token
Is there an Inbound Non Posted Request
with an earlier time stamp?
Yes
Do Not Assign Token
Allow previous Transaction to Complete
No
Assign Token
Inbound Completion in ICPLHQ
Is the relaxed order bit set in the header
and the Enable Relaxed Ordering bit set
in the ATUCR?
Yes
Assign Relaxed Order Token
No
Check for earlier Posted Request
Is there an Inbound Posted Request with
an earlier time stamp?
Yes
Do Not Assign Token
Allow previous Transaction to Complete
No
Assign Token
Is there and Inbound Completion with
and earlier timestamp
Yes
Do Not Assign Token
Allow previous Transaction to Complete
No
Assign Token
Table 128. Outbound Transaction Ordering Summary
Transaction at Head of Queue
Question
Answer
Action
Outbound Posted in OPHQ
Is there an Outbound Posted Request
with an earlier time stamp?
Yes
Do Not Assign Token
Allow previous Transaction to Complete
No
Assign Token
Outbound Non Posted Request in
ONPHQ
Is there an Outbound Posted Request
with an earlier time stamp?
Yes
Do Not Assign Token
Allow previous Transaction to Complete
No
Assign Token
Is there an Outbound Non Posted
Request with an earlier time stamp?
Yes
Do Not Assign Token
Allow previous Transaction to Complete
No
Assign Token
Outbound Completion in the
OCPLHQ
Is there an Outbound Posted Request
with an earlier time stamp?
Yes
Do Not Assign Token
Allow previous Transaction to Complete
No
Assign Token
Is there an Outbound Completion with an
earlier time stamp?
Yes
Do Not Assign Token and allow
previous Transaction to Complete
No
Assign Token