Glossary comparison
ACE vs AXI: what is the difference?
The difference
AXI is the base read and write protocol, with no notion of other managers' caches. ACE is AXI plus snoop channels and coherency signalling.
ACE adds coherence signalling on top of AXI so that caches can share memory. Plain AXI carries no coherence information.
The two terms
ACE
The AMBA extension that adds snoop channels and cache state signalling to AXI, allowing multiple caching masters to maintain hardware coherency over a shared interconnect.
AXI
The high-performance AMBA protocol using five independent channels for read and write address, data and response, supporting burst transfers, multiple outstanding transactions and out-of-order completion.
Side by side
| Field | ACE | AXI |
|---|---|---|
| Stands for | AXI Coherency Extensions | Advanced eXtensible Interface |
| Type | Acronym | Acronym |
| Domain | Design & Architecture | Design & Architecture |
| Group | Interconnect and fabric | Interconnect and fabric |