Service manual

B-24 AlphaServer GS80/160/320 Service Manual
B.10 Coherency Storage and Coherency Flow
The following sections describe how various transactions use the system
coherency storage elements as they progress through the system.
B.10.1 Local Read Transactions
Figure B– 6 Local Read Coherency Store Flow
Q0: Visit Directrory
Dtag, TTT and
IOP Tag store
via ArbBus.
Q1
Probe
Packet
(Fwd Rd)
Q2
Dirty
Data
Q1: VisitTTT
via
ArbBus
Source/Home QBB
Q1: Fwd Rd steered
directly to
Dirty Processor.
QBB of Dirty Processor
Q2: Fill steered
directly to
requesting
processor.
Q1 Q1
Response
Packet