Procedures

Commands

See Also

Nodes are the building blocks for waveform file. You can create new nodes or modify existing nodes.

The Quartus^® II software contains the following nodes:

• Input Nodes, which represent input logic driven by a pin or a state machine
• Output Nodes, which represent output logic that feeds an output pin or a state machine
• Buried Nodes, which represent logic that does not drive out to a pin
• Groups, which are an arbitrary combination of nodes that are displayed and treated as a unit
• Buses, which are groups of related nodes that the Compiler recognizes
• Bidir Nodes, which represent either input logic drive by a pin or a state machine, or output logic that feeds an output pin or a state machine.

Buried, input, and output nodes consist of a node handle that shows the type, a node or a group name, and a waveform. A group consists of its I/O type and a waveform. In a waveform file, the Handle icon indicates if the waveform represents a node or a group, and if it is buried, bidirectional, input, or output.

Input Nodes

In a waveform file, an input node is an input vector that is used for simulation. It can represent an input pin or the portion of a bidirectional pin that drives in.

The waveforms of input nodes (other than machine-type nodes) can have the following logic levels:

• Forcing low (0)
• Forcing high (1)
• Forcing unknown (X)
• High Impedance (Z)
• Uninitialized (U)
• Weak unknown (W)
• Weak low (L)
• Weak high (H)
• Don't care (DC)

An input state machine node represents a state machine that is defined in another design file of the project.

Groups

A group has no special meaning in a waveform file. It is simply a convenience for representing multiple nodes.

A group waveform shows the combined logic levels of its member nodes. A group that consists of the bits of a state machine created in the project's design files can appear in the default waveform file, and the group value shown within the waveform can be represented as either a logic level or as an equivalent state name.

Buried Nodes

The waveforms of buried nodes (other than machine-type nodes) can have the same logic levels as input nodes. A buried-type state machine can be used to define additional logic that exists between inputs and outputs.

State Machines

The waveform of a node with a node type of machine contains the names of states and represents the different states of a state machine. A state machine waveform is not a group, and cannot be ungrouped.

Bidir Nodes

In the Quartus II software, bidirectional nodes require only one channel, not two.

Working with Nodes & Groups in the Waveform Editor

To modify your waveform file, you can create a new node, delete a node or a group, change the node or I/O type of an existing node. When working with groups, you can combine nodes to create a group, or you can ungroup a group. You can also sort node and group names in a waveform file.

You can edit and find text in node names.

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