System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-186
ID021414
Non-Confidential
Usage constraints
This register is accessible as follows:
Configurations
CLIDR is architecturally mapped to AArch64 register CLIDR_EL1. See
Cache Level ID Register
on page 4-44
.
There is one copy of this register that is used in both Secure and
Non-secure states.
Attributes
CLIDR is a 32-bit register.
Figure 4-93
shows the CLIDR bit assignments.
Figure 4-93 CLIDR bit assignments
Table 4-183
shows the CLIDR bit assignments.
To access the CLIDR:
EL0
(NS)
EL0
(S)
EL1
(NS)
EL1
(S)
EL2
EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
-
RO
RO
RO
RO
RO
LoUIS
RES
0
Ctype3
Ctype2
Ctype1
31 30 29
27 26
24 23
21 20
9 8
6 5
3 2
0
LoUU
LoC
RES
0
Table 4-183 CLIDR bit assignments
Bits
Name
Function
[31:30]
-
Reserved,
RES
0.
[29:27]
LoUU
Indicates the Level of Unification Uniprocessor for the cache hierarchy:
0b0001
L1 cache is the last level of cache that must be cleaned or invalidated when cleaning or
invalidating to the point of unification for the processor.
[26:24]
LoC
Indicates the Level of Coherency for the cache hierarchy:
0b0001
L2 cache not implemented.
0b0010
A clean to the point of coherency operation requires the L1 and L2 caches to be cleaned.
[23:21]
LoUIS
Indicates the Level of Unification Inner Shareable for the cache hierarchy:
0b001
L2 cache.
L2 cache is the last level of cache that must be cleaned or invalidated when cleaning or
invalidating to the point of unification for the Inner Shareable shareability domain.
[20:6]
-
Reserved,
RES
0.
[8:6]
Ctype3
a
Indicates the type of cache if the processor implements L3 cache:
0b000
L3 cache not implemented.
[5:3]
Ctype2
Indicates the type of cache if the processor implements L2 cache:
0b000
L2 cache is not implemented.
0b100
L2 cache is implemented as a unified cache.
[2:0]
Ctype1
Indicates the type of cache implemented at L1:
0b011
Separate instruction and data caches at L1.
a. If software reads the Cache Type fields from Ctype1 upwards, after it has seen a value of
0b000
, no caches exist at further-out levels of the
hierarchy. So, for example, if Ctype2 is the first Cache Type field with a value of
0b000
, the value of Ctype3 must be ignored.