Hitachi 9900 User Manual

Page of 85
17
Hi-Star
Architecture – An
Internal Switched
Hierarchical Star Network
The Internal Hi-Star
A rc h i t e c t u re
The internal Hi-Star architecture consists of two separate networks: the Cache
Hierarchical Star Network (C-HSN) and the Control Memory Hierarchical Star Network
(CM-HSN). 
The Cache Hierarchical Star Network 
The C-HSN is the network used for transferring data to and from the main global data
cache. The C-HSN can also be broken down into two component networks: the processor
paths to the C-HSN and the actual C-HSN (as shown previously in Figure 2). Figure 16
p rovides a detailed illustration of the processor paths and the C-HSN of a Hitachi Fre e d o m
St o r a g e
Lightning 9900
V Series Lightning 9970V
system. 
4
Figure 16 – The C-HSN
of a Lightning 9970V
system provides fully
redundant switched
access to cache from all
channel adapters.