- [SOLVED] When Is It Safe to Override IY Register?
- 29 Oct 2018 11:52:13 am
- Last edited by biergaizi on 01 Nov 2018 07:00:24 am; edited 1 time in total
I understand that the IY register is used by the TI-OS to address system flags and crucial for normal system operation, I also know that IY can be borrowed by the ASM programmer when necessary, provides it is eventually restored. But exactly WHEN is it safe to do so?
Do I need to just simply restoring IY before a system call? I wrote a program that saves and restores IY at the beginning/end of system call and execution, and program seems to work without problems, but I'm afraid of interrupts. Do system interrupts use IY? Should they be disabled during the entire duration when IY is being commandeered ?
Do I need to just simply restoring IY before a system call? I wrote a program that saves and restores IY at the beginning/end of system call and execution, and program seems to work without problems, but I'm afraid of interrupts. Do system interrupts use IY? Should they be disabled during the entire duration when IY is being commandeered ?