Level 2 Memory System
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
7-16
ID021414
Non-Confidential
7.4.4
CHI transaction IDs
Table 7-14
shows the CHI transaction IDs used for each type of transaction.
7.4.5
CHI nodes
CHI transactions are sent to a specific node in the interconnect based on the:
•
Type of access.
•
Address of the access.
•
Settings of the System Address Map.
Addresses that map to an HN-F node can be marked as cacheable memory in the page tables,
and can take part in the cache coherency protocol. Addresses that map to an HN-I or MN must
be marked as device or non-cacheable memory.
Table 7-14 CHI transactions
Transaction ID
Description
000nnxxx
Transaction from core nn. Can be a:
•
Read transaction.
•
Write transaction.
•
Cache maintenance transaction.
•
DVM transaction.
•
Barrier transaction.
001001xx
Transaction from the ACP interface. Can be a read or write.
00101110
Barrier generated in response to a DVM sync snoop from the interconnect.
0100xxxx
Eviction from L1 or L2 cache. The number of IDs used depends on the configuration.