An AXI port, in the context of the provided reference, specifically refers to an AXI Access Port (AXI-AP), which is a component designed to enable debugging access to memory systems using the AXI protocol.
Understanding the AXI Access Port (AXI-AP)
The AXI Access Port (AXI-AP) plays a crucial role in debug architectures, particularly within the Arm Debug Access Port (DAP) framework. It acts as a bridge allowing external debug tools to interact with system memory and peripherals that use the AXI interface.
Key Functionality:
- Debugger Interface: The AXI-AP provides an interface that a debugger can utilize to perform memory and register accesses on the target system.
- AXI Bus Master: It operates as an AXI master. This means it can initiate read and write transactions over an AXI bus, allowing the debugger to access memory locations or control peripherals connected to that bus.
- Connectivity: It can be connected to various memory systems or peripherals that use the AXI protocol, often requiring a suitable bridging component to handle specific system architectures or different AXI widths/speeds.
Features of the AXI-AP
According to the Arm documentation reference:
- Supports a single clock domain. This simplifies the design and integration of the AXI-AP within the debug system.
Role in Debugging
In a typical debug setup, the AXI-AP is part of the Debug Access Port (DAP). The debugger connects to the DAP, which then uses the AXI-AP to communicate with the target system's AXI-based components (like memory controllers, system-on-chip peripherals, etc.). This allows developers to inspect memory contents, modify variables, or access control registers during debugging sessions.
Think of the AXI-AP as the debugger's dedicated doorway into the system's AXI bus, enabling powerful low-level access for analysis and control.
