
DR
AFT
DR
AFT
DRAFT
DR
D
RAFT
DRAFT
DRA
FT DRAF
D
RAFT DRAFT DRAFT DRAFT DRAFT D
DRAFT
D
RAFT DRA
FT DRAFT DRAFT DRAFT DRA
UM10360_0
© NXP B.V. 2009. All rights reserved.
User manual
Rev. 00.06 — 5 June 2009
623 of 808
NXP Semiconductors
UM10360
Chapter 34: Appendix: Cortex-M3 User Guide
•
If
n
is 33 or more and the carry flag is updated, it is updated to 0.
2.3.4.3
LSL
Logical shift left by
n
bits moves the right-hand
32
-
n
bits of the register
Rm
, to the left by
n
places, into the left-hand
32
-
n
bits of the result. And it sets the right-hand
n
bits of the
result to 0. See
.
You can use he LSL #
n
operation to multiply the value in the register
Rm
by 2
n
, if the value
is regarded as an unsigned integer or a two’s complement signed integer. Overflow can
occur without warning.
When the instruction is
LSLS
or when LSL #
n
, with non-zero
n
, is used in
Operand2
with
the instructions
MOVS
,
MVNS
,
ANDS
,
ORRS
,
ORNS
,
EORS
,
BICS
,
TEQ
or
TST
, the carry flag is updated
to the last bit shifted out, bit[
32
-
n
], of the register
Rm
. These instructions do not affect the
carry flag when used with
LSL #0
.
Note
•
If
n
is 32 or more, then all the bits in the result are cleared to 0.
•
If
n
is 33 or more and the carry flag is updated, it is updated to 0.
2.3.4.4
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
When the instruction is
RORS
or when ROR #
n
is used in
Operand2
with the instructions
MOVS
,
MVNS
,
ANDS
,
ORRS
,
ORNS
,
EORS
,
BICS
,
TEQ
or
TST
, the carry flag is updated to the last bit
rotation, bit[
n
-1], of the register
Rm
.
Note
Fig 139. LSR#3
&DUU\
)ODJ
Fig 140. LSL#3
&DUU\
)ODJ