Re: Understanding assembler instructions

Christian Christmann <plfriko@xxxxxxxx> écrivait news:4361fcbd$0$21955
$9b4e6d93@xxxxxxxxxxxxxxxxxxxxxxxxxx:

> In a CALL instruction, the high 2 bits are the instruction code and the
> low 30 bits are s signed word offset. What are the hex addresses for
> X, Y and Z?

There are several forms of CALL. The one for "Direct
Code CALL" is a one-Byte Opcode, followed by a dWord.

This dWord is the relative Displacement from the first
Byte, after the Call Instruction, to the targetted
location.

Example

> call Code0411860 ; E8 EC FF 00 00

.... means (E8) CALL "+65516" (0FFEC)

> call Code0401F80 ; E8 D5 FF FF FF

.... means CALL "-43" (0FFFF_FFD5)


Betov.

< http://rosasm.org >





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