Intel® Quartus® Prime Standard Edition User Guide: Debug Tools

ID 683552
Date 9/24/2018
Document Table of Contents State-Based Triggering

With state-based triggering, a state diagram organizes the events that trigger the acquisition buffer. The states capture all actions that the acquisition buffer performs, and each state contains conditional expressions that define transition conditions.

Custom state-based triggering grants control over triggering condition arrangement. Because the Logic Analyzer only captures samples of interest, custom state-based triggering allows for more efficient use of the space available in the acquisition buffer.

To help you describe the relationship between triggering conditions, the state-based triggering flow provides tooltips within the flow GUI. Additionally, you can use the Signal Tap Trigger Flow Description Language, which is based upon conditional expressions.

Figure 75. State-Based Triggering Flow

Notes to figure:

  1. You can define up to 20 different states.
  2. The logic analyzer evaluates external trigger inputs that you define before any conditions in the custom state-based triggering flow.

Each state allows you to define a set of conditional expressions. Conditional expressions are Boolean expressions that depend on a combination of triggering conditions, counters, and status flags. You configure the triggering conditions within the Setup tab. The Signal Tap Logic Analyzer custom-based triggering flow provides counters and status flags.

Within each conditional expression you define a set of actions. Actions include triggering the acquisition buffer to stop capture, a modification to either a counter or status flag, or a state transition.

Trigger actions can apply to either a single segment of a segmented acquisition buffer or to the entire non-segmented acquisition buffer. Each trigger action provides an optional count that specifies the number of samples the buffer captures before the logic analyzer stops acquisition of the current segment. The count argument allows you to control the amount of data the buffer captures before and after a triggering event occurs.

Resource manipulation actions allow you to increment and decrement counters or set and clear status flags. The logic analyzer uses counter and status flag resources as optional inputs in conditional expressions. Counters and status flags are useful for counting the number of occurrences of certain events and for aiding in triggering flow control.

The state-based triggering flow allows you to capture a sequence of events that may not necessarily be contiguous in time. For example, a communication transaction between two devices that includes a hand shaking protocol containing a sequence of acknowledgments.