System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-48
ID021414
Non-Confidential
MRS <Xt>, CTR_EL0 ; Read CTR_EL0 into Xt
Register access is encoded as follows:
4.3.27
Data Cache Zero ID Register
The DCZID_EL0 characteristics are:
Purpose
Indicates the block size written with byte values of zero by the
DC ZVA
(Cache Zero by Address), system instruction.
Usage constraints
This register is accessible as follows:
Configurations
There are no configuration notes.
Attributes
DCZID_EL0 is a 32-bit register.
Figure 4-25
shows the DCZID_EL0 bit assignments.
Figure 4-25 DCZID_EL0 bit assignments
Table 4-61
shows the DCZID_EL0 bit assignments.
To access the DCZID_EL0:
MRS <Xt>, DCZID_EL0 ; Read DCZID_EL0 into Xt
Table 4-60 CTR_EL0 access encoding
op0
op1
CRn
CRm
op2
11
011
0000
0000
001
EL0
EL1
(NS)
EL1
(S)
EL2
EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
RO
RO
RO
RO
RO
RO
4
RES
0
3
5
BlockSize
DZP
0
63
Table 4-61 DCZID_EL0 bit assignments
Bits
Name
Function
[63:5]
-
Reserved,
RES
0.
[4]
DZP
Prohibit the
DC ZVA
instruction:
0
DC ZVA
instruction permitted.
1
DC ZVA
instruction is prohibited.
[3:0]
BlockSize
Log2 of the block size in words:
0b0100
The block size is 16 words.