stm8, cpu register, cosmic

[MykolaLevun]

Hello

How can I access CPU registers using the Cosmic compiler?

For example, when I access register A, the compiler throws an error A is undefined (This is shown in the picture and also the project files).

[Ans · Accepted solution]

You've to define address for any register. Check datasheet and see what's the address of A register and then define it accordingly. 
Checkout this guide: https://lujji.github.io/blog/bare-metal-programming-stm8/

[SofLit]

Hello,

If "A" is a an internal core register you need to access it in assembly language.

If "A" is a peripheral register you need to define the address of "A" and access it by pointer in C.