ARM VERSION 1.2 manual ...

ARM Instruction Reference
ARM DUI 0068B Copyright © 2000, 2001 ARM Limited. All r ights reserved. 4-25
ASR
Arithmetic shift right by
n bits divides the value contained in Rm by 2n, if the contents
are regarded as a two’s complement signed integer. The original bit[31] is copied into
the left-hand
n bits of the register.
LSR and LSL
Logical shift right by
n bits divides the value contained in Rm by 2n, if the contents are
regarded as an unsigned integer. The left-hand
n bits of the register are set to 0.
Logical shift left by
n bits multiplies the value contained in Rm by 2n, if the contents ar e
regarded as an unsigned integer. Overflow may occur without warning. The right-hand
n bits of the register are set to 0.
ROR
Rotate right by
n bits moves the right-hand n bits of the register into the left-hand n bits
of the result. At the same time, all other bits are moved right by
n bits (see Figure4-1).
Figure4-1 ROR
RRX
Rotate right with extend shifts the contents of
Rm right by one bit. The carry flag is
copied into bit[31] of
Rm (see Figure4-2 on page 4-26).
The old value of bit[0] of
Rm is shifted out to the carry flag if the S suffix is specified (s ee
The carry flag on page 4-26).
31 10
Carry
Flag
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