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C2000 Assembly

Milind Bapat
Intellectual 345 points

In following instruction, why @ is added before XAR6, based on way instruction executes, it is ACC value getting copied in XAR6, there is no indirect addressing involved here?

MOVL         @XAR6, ACC

  • 0
    Intellectual 995 points

    Hi,

    This is not indirect addressing, simply XAR6 = ACC.

    SPRU430F, page 100:

    Note: When writing assembly code, the “@” symbol in front of the register is optional. For example:

    “MOVL ACC,@P” or “MOVL ACC,P”. The disassembler will use the @ to indicate operands that are

    “loc16” or “loc32”. For example, MOVL ACC, @P is the MOVL ACC, loc32 instruction and MOVL @ACC,

    P is the MOVL loc32, P instruction.

     

    Janos

  • 0
    Intellectual 345 points
    Thanks Janos,
    I did not get the difference in MOVL ACC,loc32 and MOVL loc32,P in your explanation., Are you saying that @is used to define source and destination?
  • 0 in reply to Milind Bapat
    Intellectual 995 points
    No, it means, that for copying ACC to XAR6 you can use two different opcodes that will result in the same operation. By placing the @ in front of the destination register name the disassembler tells you that the compiler used the MOV loc32, P instruction. But it does not make any difference considering the result.