UM10429
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User manual
Rev. 1 — 20 October 2010
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NXP Semiconductors
UM10429
Chapter 19: Appendix LPC1102 ARM Cortex-M0 reference
19.4.7.6.4
Condition flags
This instruction does not change the flags.
19.4.7.6.5
Examples
MRS
R0, PRIMASK ; Read PRIMASK value and write it to R0
19.4.7.7 MSR
Move the contents of a general-purpose register into the specified special register.
19.4.7.7.1
Syntax
MSR
spec_reg
,
Rn
where:
Rn
is the general-purpose source register.
spec_reg
is the special-purpose destination register: APSR, IPSR, EPSR, IEPSR,
IAPSR, EAPSR, PSR, MSP, PSP, PRIMASK, or CONTROL.
19.4.7.7.2
Operation
MSR updates one of the special registers with the value from the register specified by
Rn
.
See
19.4.7.7.3
Restrictions
In this instruction,
Rn
must not be SP and must not be PC.
19.4.7.7.4
Condition flags
This instruction updates the flags explicitly based on the value in
Rn
.
19.4.7.7.5
Examples
MSR
CONTROL, R1 ; Read R1 value and write it to the CONTROL register
19.4.7.8 NOP
No Operation.
19.4.7.8.1
Syntax
NOP
19.4.7.8.2
Operation
NOP performs no operation and is not guaranteed to be time consuming. The processor
might remove it from the pipeline before it reaches the execution stage.
Use NOP for padding, for example to place the subsequent instructions on a 64-bit
boundary.
19.4.7.8.3
Restrictions
There are no restrictions.