Assembly notation: "K"

Jon Zarate

I was reading the slaa534.pdf and I came across this "K" thing. For example:

ADDX K(R4), R5

I have seen & and # before, but not a K. What does it mean ?

It appears several times on pages 67 & 68.

Thank you.

over 10 years ago

0 George Mock over 10 years ago

TI__Guru**** 253380 points

I searched carefully through http://www.ti.com/lit/ug/slau208o/slau208o.pdf . I can find no instance of this K notation. Perhaps you meant a different book, or a different version of this book?

Thanks and regards,

-George

0 Jon Zarate over 10 years ago in reply to George Mock

Expert 1190 points

Thanks god you noticed. I made a mistake there, I meant slaa534.pdf.

Sorry, main post corrected.

0 Archaeologist over 10 years ago

TI__Guru* 84285 points

It doesn't mean anything; it's just a variable name.

0 Jon Zarate over 10 years ago in reply to Archaeologist

Expert 1190 points

Archaeologist said:
It doesn't mean anything; it's just a variable name.

Are you sure ? I think you mean this ones:

MOVA X, R5

Being X a variable.

0 Archaeologist over 10 years ago in reply to Jon Zarate

TI__Guru* 84285 points

I'm sure. The syntax "n(R4)" is indexed addressing; usually n is a constant immediate integer like 0, 1, 2.
However, the section you're looking at deals with relocations. You can put a variable name there instead of the constant immediate integer. So, when you use "K(R4)", the linker looks for a symbol named K and puts its address in the constant field of the encoding.

0 Jon Zarate over 10 years ago in reply to Archaeologist

Expert 1190 points

Oh! That would make sense.

However, the address of the symbol ? Not the value ?

Also, would that code be the same as this code below ?

MOV.W  #K, R4
ADDX   R4, R5

0 Archaeologist over 10 years ago in reply to Jon Zarate

TI__Guru* 84285 points

The assembler and linker always deal with the addresses of symbols, never the contained value. The instruction it is used in determines what to do with the address, perhaps by loading the contents of memory at that address (it's "value").

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Assembly notation: "K"