B2.98
Translation Table Base Register 1, EL1
The TTBR1_EL1 characteristics are:
Purpose
Holds the base address of translation table 1, and information about the memory it occupies.
This is one of the translation tables for the stage 1 translation of memory accesses at EL0 and
EL1.
Usage constraints
This register is accessible as follows:
EL0 EL1
(NS)
EL1
(S)
EL2 EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
RW
RW RW RW
RW
Any of the fields in this register are permitted to be cached in a TLB.
Configurations
TTBR1_EL1 is architecturally mapped to AArch32 register TTBR1 (NS). See
B1.116 Translation Table Base Register 1
.
Attributes
TTBR1_EL1 is a 64-bit register.
BADDR[47:x]
ASID
47
48
0
63
Figure B2-69 TTBR1_EL1 bit assignments
ASID, [63:48]
An ASID for the translation table base address. The TCR_EL1.A1 field selects either
TTBR0_EL1.ASID or TTBR1_EL1.ASID.
BADDR[47:x], [47:0]
Translation table base address, bits[47:x]. Bits [x-1:0] are
RES0
.
x is based on the value of TCR_EL1.T0SZ, the stage of translation, and the memory translation
granule size.
For instructions on how to calculate it, see the
Arm
®
Architecture Reference Manual Armv8, for
Armv8-A architecture profile
.
The value of x determines the required alignment of the translation table, that must be aligned to
2
x
bytes.
If bits [x-1:0] are not all zero, this is a misaligned Translation Table Base Address. Its effects are
CONSTRAINED UNPREDICTABLE
, where bits [x-1:0] are treated as if all the bits are zero. The value
read back from those bits is the value written.
To access the TTBR1_EL1:
MRS <Xt>, TTBR1_EL1 ; Read TTBR1_EL1 into Xt
MSR TTBR1_EL1, <Xt> ; Write Xt to TTBR1_EL1
Register access is encoded as follows:
B2 AArch64 system registers
B2.98 Translation Table Base Register 1, EL1
100236_0100_00_en
Copyright © 2015–2017, 2019 Arm Limited or its affiliates. All rights
reserved.
B2-548
Non-Confidential
Summary of Contents for Cortex-A35
Page 4: ......
Page 18: ......
Page 26: ......
Page 27: ...Part A Functional Description ...
Page 28: ......
Page 145: ...Part B Register Descriptions ...
Page 146: ......
Page 573: ...Part C Debug ...
Page 574: ......
Page 845: ...Part D Appendices ...
Page 846: ......