AXI Protocol Overview

The Advanced eXtensible Interface (AXI) is the highest performance AMBA interface, designed for high-frequency, high-bandwidth interconnects in modern SoCs.

Key Features

  • Separate Address/Control and Data Phases: Control and data flow independently.
  • Unaligned Data Transfers: Uses byte strobes to handle unaligned start addresses.
  • Burst-based Transactions: Only the start address is issued; the data follows in a burst.
  • Separate Read and Write Channels: Full duplex communication (simultaneous Read/Write).
  • Out-of-Order Transaction Completion: Allows high efficiency with disparate Slave latencies.

Comparison: AHB vs AXI

Feature AHB AXI
Topology Shared Bus Multi-channel / Crossbar
Channels Shared R/W 5 Independent Channels
Performance Medium High