Yes, AXI is considered full duplex because it supports simultaneous read and write operations.
The Advanced eXtensible Interface (AXI) protocol, a key part of ARM's AMBA (Advanced Microcontroller Bus Architecture) specification, is designed with independent channels for different types of transactions. This design choice is fundamental to its performance capabilities.
Based on the provided reference:
- Independent Channels: AXI features completely separate channels for read and write operations. This is a significant difference compared to some older bus protocols.
- Full Duplex Operation: Because read and write data can flow simultaneously over their respective independent channels, AXI enables a "full duplex mode of data transportation."
- Simultaneous Transactions: This means that data reads and data writes can occur at the same time.
- Performance Benefit: The ability to perform reads and writes concurrently contributes to enhanced performance, potentially offering a significant boost (as the reference notes, up to a "2x boost over AHB in any circumstances" due to this capability).
This architecture contrasts with protocols where read and write data share the same channels, often requiring transactions to be sequential (half duplex or simplex depending on the exact implementation).
For more details on AXI's features and comparisons with other bus protocols like AHB, you can refer to resources like the one cited here.
In summary, AXI's independent read and write channels are the key feature that allows it to operate in full duplex mode, facilitating simultaneous data transfer in both directions.
