Waveform Viewer

The waveform viewer displays signal transitions over time. It’s available in both the web and desktop apps.

Reading waveforms

Each selected signal gets a horizontal lane. The lane shows value transitions as lines and steps:

• Single-bit signals (std_logic, bit) — drawn as high/low waveforms
• Vector signals (std_logic_vector) — drawn as bus-style bars with the value printed inside

Signal colors

Signals are color-coded by their current logic state:

Value	Color	Meaning
'0', '1'	Green	Driven logic level
'Z'	Cyan	High impedance (tri-state)
'X'	Red	Unknown or conflict
'U'	Orange	Uninitialized
'W'	Yellow	Weak unknown
'L', 'H'	Dark green	Weak logic
'-'	Gray	Don’t care

Controls

Action	How
Zoom	Scroll wheel on the waveform area
Pan	Click and drag
Place cursor	Click on the waveform — values at that time appear next to each signal
Add signal	Check its box in the sidebar signal tree
Remove signal	Uncheck its box
Select group	Check a parent node to add all signals in that hierarchy level
Resize panels	Drag the divider between the sidebar and waveform area

Time scale

Use the time unit selector to switch between nanoseconds (ns), microseconds (us), and milliseconds (ms). Choose whichever matches the scale of your simulation.

Value formats

Vector signals can be displayed in different numeric formats:

• Hex — x"FF" (default for wide vectors)
• Binary — "11111111"
• Decimal — 255

Right-click a signal to change its display format.