amba-chi · Topic
CHI Ordering & Memory Consistency
Ordering guarantees in CHI — request ordering, completion, barriers and the consistency model the interconnect supports.
Coherence says every agent eventually agrees on a line's value; consistency says what order operations across different addresses appear to happen in. They are separate guarantees, and a system can be coherent while still allowing reorderings that surprise software. CHI's ordering rules and barrier transactions exist to give software the stronger guarantee where it needs it, and only where it needs it.