Atmel Evaluation Kit for the SAM4E Series of Flash Microcontrollers ATSAM4E-EK ATSAM4E-EK Data Sheet

SAM4E [DATASHEET]

Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14

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Operation

The register access operation in MSR depends on the privilege level. Unprivileged software can only access the
APSR. See 

. Privileged software can access all special registers.

In unprivileged software writes to unallocated or execution state bits in the PSR are ignored. 

Note:

When the user writes to BASEPRI_MAX, the instruction writes to BASEPRI only if either:
Rn is non-zero and the current BASEPRI value is 0
Rn is non-zero and less than the current BASEPRI value.

Restrictions

Rn must not be SP and must not be PC.

Condition Flags

This instruction updates the flags explicitly based on the value in Rn.

Examples

MSR

CONTROL, R1 ; Read R1 value and write it to the CONTROL register 

No Operation.

Syntax

NOP{cond}

where:

cond

is an optional condition code, see 

.

Operation

NOP does nothing. NOP is not necessarily a time-consuming NOP. The processor might remove it from the
pipeline before it reaches the execution stage.

Use NOP for padding, for example to place the following instruction on a 64-bit boundary.

Condition Flags

This instruction does not change the flags.

Examples

NOP

; No operation