Nios® V Embedded Processor Design Handbook

ID 726952
Date 11/25/2024
Public
Document Table of Contents

6.2.3.2.3.2. Power-Up Trigger Conditions

The Signal Tap logic analyzer supports a power-up trigger feature. You can use it for monitoring systems in which the Nios® V processor operates in self-booting mode, immediately after configuring the FPGA.

In self-booting mode, the Nios® V processor begins software execution immediately from system memory without a debugger to start, stop, and load the processor's run-time memory. Manually starting the Signal Tap logic analyzer can result in a slower reaction speed and potentially miss the specified triggering Program Counter. The Signal Tap logic analyzer can begin data acquisition with the power-up trigger before the processor is out of reset.

Follow these steps to begin capturing processor execution starting from the reset vector:
  1. Select the processor system reset as the power-up trigger.
  2. The power-up trigger appears as a child instance under the parent Signal Tap instances, and all trigger patterns are repopulated with Don’t Care.
  3. Specify the same trigger patterns again.
Figure 110. Power-Up Triggers