Texas Instruments MSP430x1xx User Manual page 89

* NOP No operation
Syntax NOP
Operation None
Emulation MOV
Description No operation is performed. The instruction may be used for the elimination of
instructions during the software check or for defined waiting times.
Status Bits Status bits are not affected.
The NOP instruction is mainly used for two purposes:
-
-
Note: Emulating No-Operation Instruction
Other instructions can emulate the NOP function while providing different
numbers of instruction cycles and code words. Some examples are:
However, care should be taken when using these examples to prevent
unintended results. For example, if MOV 0(R4), 0(R4) is used and the value
in R4 is 120h, then a security violation will occur with the watchdog timer
(address 120h) because the security key was not used.
#0, R3
To fill one, two, or three memory words
To adjust software timing
Examples:
MOV #0,R3
MOV 0(R4),0(R4)
MOV @R4,0(R4)
BIC #0,EDE(R4)
JMP $+2
BIC #0,R5
Instruction Set
; 1 cycle, 1 word
; 6 cycles, 3 words
; 5 cycles, 2 words
; 4 cycles, 2 words
; 2 cycles, 1 word
; 1 cycle, 1 word
RISC 16−Bit CPU
3-53