cannot understand SYS instruction for S12XE

[Xbot]

hi,

i'm having a hard time understanding the purpose of the SYS instruction. this is supposed to an MPU call. is this an interrupt call where you can enter supervisor state? how about when i want to set the descriptors for XGATE code execution, how do do it?

there is also interrupt vectors for access errors ?

[Steve]

SYS is an additional "software interrupt" that does the same kind of thing as SWI. It was added because SWI is already heavily used in debugging environments. The intent of SYS is to provide a separate software interrupt for use by the system that will not cause confusion and difficulties for development tools.

All interrupts including SYS return you to supervisor state.

Read AN3242 for more information about the MPU and SYS and Supervisor and User State.