The Nios® II processor architecture supports a Joint Test Action Group (JTAG) debug module that provides on-chip emulation features to control the processor remotely from a host PC. PC-based software debugging tools, such as the Nios II Embedded Design Suite (EDS), communicate with the JTAG debug module and enable designers to do the following:

  • Downloading programs to memory
  • Starting and stopping execution
  • Setting breakpoints and watchpoints
  • Analyzing registers and memory
  • Collecting real-time execution trace data

The debug module connects to the JTAG circuitry built into all Altera® FPGAs (shown in Figure 1) and connects to the host PC via a download cable, such as the Altera USB BlasterTM cable (included in the Nios II development kits) or a third-party system analyzer probe.

Figure 1. Nios II JTAG Debug Module

Software developers can access the core from a host software such as the Nios II EDS (included in all Nios II development kits) or through an integrated design environment (IDE) and debugger from Altera's embedded software tools partners.

Customers requiring a more advanced set of debugging features can upgrade to a third-party probe solution.

More information regarding the JTAG debug module and software debugging using the Nios II IDE is available on the Nios II processor handbook.


Return to the Nios II processor page.