Datasheet
UM10398 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2014. All rights reserved.
User manual Rev. 12.3 — 10 June 2014 479 of 547
NXP Semiconductors
UM10398
Chapter 28: LPC111x/LPC11Cxx Appendix: ARM Cortex-M0 reference
28.5.3.3.4 ROR
Rotate right by n bits moves the left-hand 32-n bits of the register Rm, to the right by n
places, into the right-hand 32-n bits of the result, and it moves the right-hand n bits of the
register into the left-hand n bits of the result. See Figure 28–106
.
When the instruction is RORS the carry flag is updated to the last bit rotation, bit[n-1], of
the register Rm.
Remark:
• If n is 32, then the value of the result is same as the value in Rm, and if the carry flag
is updated, it is updated to bit[31] of Rm.
• ROR
with shift length, n, greater than 32 is the same as
ROR
with shift length n-32.
28.5.3.4 Address alignment
An aligned access is an operation where a word-aligned address is used for a word, or
multiple word access, or where a halfword-aligned address is used for a halfword access.
Byte accesses are always aligned.
There is no support for unaligned accesses on the Cortex-M0 processor. Any attempt to
perform an unaligned memory access operation results in a HardFault exception.
28.5.3.5 PC-relative expressions
A PC-relative expression or label is a symbol that represents the address of an instruction
or literal data. It is represented in the instruction as the PC value plus or minus a numeric
offset. The assembler calculates the required offset from the label and the address of the
current instruction. If the offset is too big, the assembler produces an error.
Remark:
• For most instructions, the value of the PC is the address of the current instruction plus
4 bytes.
• Your assembler might permit other syntaxes for PC-relative expressions, such as a
label plus or minus a number, or an expression of the form [PC, #imm].
Fig 106. ROR #3
&DUU\
)ODJ