Unaligned and Mixed-endian Data Access Support
ARM DDI 0301H Copyright © 2004-2009 ARM Limited. All rights reserved. 4-10
ID012310 Non-Confidential, Unrestricted Access
Figure 4-9 Store halfword, big-endian
If strict alignment fault checking is enabled and Address bit 0 is not zero, then a Data Abort is
generated and the MMU returns a Misaligned fault in the Fault Status Register.
4.3.10 Load word, little-endian
The addressed byte-quad is loaded from memory into the 32-bit general-purpose register so that
the least-significant addressed byte in memory appears in bits [7:0] of the ARM register, as
Figure 4-10 shows.
Figure 4-10 Load word, little-endian
If strict alignment fault checking is enabled and Address bits [1:0] are not zero, then a Data
Abort is generated and the MMU returns a Misaligned fault in the Fault Status Register.
4.3.11 Load word, big-endian
The addressed byte-quad is loaded from memory into the 32-bit general-purpose register so that
the most significant addressed byte in memory appears in bits [31:24] of the ARM register, as
Figure 4-11 on page 4-11 shows.
Register
31 23 15 7 0
x x B0 B1
B1
B0
Memory
Address
A[31:0]
70
+1 lsbyte
msbyte
b1
b0
Memory Register
31 23 15 7 0
Address
A[31:0]
70
b3 b2 b1 b0
b2
+1
msbyte
lsbyte
b3
+2
+3
To Next Page
Loading...
Need help?
General
