Chapter 10 Memory Subsystem.pdf

Status:
There are n pending
requests stored in
the 8 FIFO queues.
Cx Win
How many simultaneous
eligible requests are there?
X = [0:2]
0 for class 0
1 for class 1
2 for class 2
0 request A
1 request B
Yes
2 reqs HIGHPRIOVECTOR?
No
Yes
3 reqs HIGHPRIOVECTOR?
No
4 reqs HIGHPRIOVECTOR?
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Figure 10-74. Generic Arbitration Decision
At this time, it is ensure that for each group containing a req:
The request is part of the burst, the BURSTCOMPLETE
ttribute is set, and the full burst is not available
Yes
No
LRU policy
LRU policy
LRU policy
B
B
B
B
B
B
Go back to the
arbitration decision
Move to the arbitration
granularity process
Is there a priority between
the 2 groups containing the 2
requests?
The least-recently-used thread
which made the request is
serviced.
Class 0 - class 1
(a simultaneous decision can
occur between 2 groups, 1 group,
or none).
Class 2
(a simultaneous decision
can occur between 4 reqs
stored in the 4 groups, 3 reqs
stored in 3 groups, etc.).
SPRUGN4L–May 2010–Revised June 2011 Memory Subsystem
Copyright © 2010–2011, Texas Instruments Incorporated
sdrc-031
2275