MSP430 - NOP

Mikael Hygren

Other Parts Discussed in Thread: CC1120

Hi!

I am using code composer studio and imported software examples to communicate with CC1120 and a macro defined in this file uses a NOP() operation and ccs says it cannot recognize it. Is this operation incompatible with ccs and only works for the compiler in IAR? Can I just use delaycycles(1) instead?

over 12 years ago

0 BrandonAzbell over 12 years ago

TI__Guru 64470 points

If you search for NOP in the sources of the CC112x software examples on the product folder, you will see the NOP() is a #define for different intrinsic operations depending on the compiler/tool chain used.

In the file swrc253a\source\components\common\msp430\hal_msp430.h, you will find a definition for NOP() for Code Composer Studio.

#define NOP() _nop()

0 Leo Hendrawan over 12 years ago

TI__Guru 56650 points

Mikael,

can you try to use instead:

#define NOP() __no_operation()

0 GURU MOORTHY over 10 years ago in reply to Leo Hendrawan

Expert 2425 points

u can directly use __no_operation();

0 Jens-Michael Gross over 10 years ago

Guru 227245 points

It should be noted that there is no real NOP instruction at all.
However, there are lots of instructions that take one clock cycle but do not make sense when used with certain parameters and do not change system state.
Like moving Rx to itself (for x=3..15).

If the status register is not important (which it isn’t for C instructions, as any required status becomes obsolete at the end of the previous instruction), then even ADD #0, Rx, AND #-1, Rx or OR #0,Rx are NOPs too.
It is even possible to do a NOP with 4 clock cycles duration and only 2 words size by making something like add #0, &0x2000. And a JMP $+2 will take one word and two clock cycles.

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MSP430 - NOP