Level 1 Memory System
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
6-21
ID021414
Non-Confidential
IPA cache RAM
The
Intermediate Physical Address
(IPA) cache RAM uses a 117-bit encoding when parity is
enabled and 114-bit encoding when parity is disabled.
Table 6-16
shows the data fields in the
IPA cache descriptor.
Table 6-16 IPA cache descriptor fields
Bits
Name
Description
[116:114]
ECC
ECC. If ECC is not configured, these bits are absent.
[113:86]
PA
Physical address.
[85:62]
IPA
Unused lower bits, page size dependent, must be zero.
[61:59]
-
Reserved, must be zero.
[58:56]
Size
The size values are:
0b011
64KB.
0b101
2MB.
0b111
512MB.
[55:40]
-
Reserved, must be zero.
[39:32]
VMID
Virtual Machine Identifier.
[31:11]
-
Reserved, must be zero.
[10]
Contiguous
Set if the pagewalk had contiguous bit set.
[9:6]
Memattrs
Memory attributes.
[5]
XN
Execute Never.
[4:3]
HAP
Hypervisor access permissions.
[2:1]
SH
Shareability.
[0]
Valid
The entry contains valid data.