assemblyinstructionsstm8

Stm8 assembly instructions


I am trying to learn some basic fw reverse engineering but I need some help. I am complete novice when it comes to asm but I do have some background on other languages.

What does the following line do? I get what cpl does but the instructions after that I don't understand.

Cpl ($ff,SP)

Am I correct that the next two lines load an address and a value to the Y and X registers?

Ldw Y,$80b0
Ldw X,#$80b2

This interrupt jupms to line 80e2?

Int $80e2

Are there any good places to learn STM8S assembly other than the ST programming manual?

I tried to find answers online but couldn't find any


Solution

  • Found the answer.

    The cpl command addresses SP in indexed mode. Detailed description can be found in STM8 PM0044 programming manual page 42.

    The interrupt jumps to that line.

    The first ldw loads whatever is in $80b0 to Y The second ldw loads the hex value 80b2 (dec 32946) to X