ARM VERSION 1.2 - Manual (Page 119)

ARM Instruction Reference
ARM DUI 0068B Copyright © 2000, 2001 ARM Limited. All rights reserved. 4-9
Flexible offset syntax
Both pre-indexed and post-indexed offsets can be either of the following:
#expr
{-}Rm{, shift}
where:
- is an optional minus sign. If - is present, the offset is subtracted from Rn .
Otherwise, the offset is added to Rn .
expr is an expression evaluating to an integer in the range –4095 to +4095.
This is often a numeric constant (see examples below).
Rm is a register containing a value to be used as the offset. Rm must not be r15.
shift is an optional shift to be applied to Rm . It can be any one of:
ASR n
arithmetic shift right n bits. 1
≤
n
≤ 32.
LSL n
logical shift left n bits. 0
≤
n
≤ 31.
LSR n
logical shift right n bits. 1 ≤
n
≤ 32.
ROR n
rotate right n bits. 1
≤
n
≤ 31.
RRX rotate right one bit, with extend.