How to Create a Timing Diagram

Mariano Olmos Martín · Updated 26 September 2026

This is a sequence for drawing a timing diagram that someone else can check: name the signals, pick a time grid, draw the levels, then mark the relationships. Worked frames for SPI, I2C, and UART are on the examples page.

What is a Timing Diagram?

A timing diagram is a graphical representation of digital signals over time. It shows how signals change state, how different signals relate to each other, and when specific events occur. Timing diagrams are essential documentation for digital electronics, embedded systems, and communication protocols.

When You Need Timing Diagrams

Documenting protocols – Show how SPI, I2C, UART, and other interfaces work
Specifying hardware behavior – Define how inputs and outputs must behave
Debugging issues – Visualize signal relationships to find problems
Teaching concepts – Help students understand digital logic
Creating datasheets – Provide timing information for components

How to Create Timing Diagrams with WavePaint

The steps below use the WavePaint editor. The same sequence works on paper. Menu names match the handbook.

Step 1: Create Your Signals

Start by adding signals to your diagram. WavePaint supports three signal types:

Bit Signal – For single-bit digital signals (clocks, enables, single-wire data)
Vector Signal – For multi-bit buses (data buses, addresses, counters)
Blank Row – For visual separation between signal groups

Use Edit → Add Signal or right-click on the canvas to add signals. Name each signal descriptively (e.g., “CLK”, “MOSI”, “DATA[7:0]”).

Step 2: Configure the Timeline

Set the number of time steps (samples) for your diagram. For simple protocols, 8-16 steps may be enough. Complex transactions might need 32 or more steps.

You can also add sub-steps for finer timing resolution. This is useful when you need to show events that happen between main clock cycles.

Step 3: Draw Your Waveforms

Use WavePaint’s paint tools to set signal states:

Click and drag to paint values (0, 1, X, Z) on bit signals
Select the value from the toolbar, then click on time steps
Use predefined patterns like clock, counter, or pulse for common signals

For vector signals, you can edit the hexadecimal value of each segment and add custom labels.

Step 4: Add Visual Elements

Enhance your diagram with annotations:

Arrows – Show cause-and-effect relationships between signals
Markers – Highlight specific timing events
Time spans – Indicate durations (setup time, hold time)
Text annotations – Add labels and explanations anywhere

Step 5: Organize with Groups

For complex diagrams, organize signals into collapsible groups:

Group by function (clocks, control, data)
Group by interface (SPI signals, I2C signals)
Group by direction (inputs, outputs)

Step 6: Apply Styling

Make your diagram visually clear:

Signal colors – Assign unique colors to differentiate signals
Segment colors – Highlight specific data phases on buses
Themes – Choose light or dark theme based on documentation style

Step 7: Export Your Diagram

Export in the format you need:

PNG – For Word documents, presentations, emails
SVG – For LaTeX documents, web pages, scalable publications
WaveDrom JSON – For WaveDrom-compatible documentation systems

Timing Diagram Best Practices

Keep It Readable

Use meaningful signal names
Group related signals together
Don’t show more signals than necessary
Use colors consistently

Show Key Timing

Use arrows to show sampling edges
Mark setup and hold times
Indicate clock-to-output delays
Label propagation delays

Annotate Clearly

Label data phases (address, command, data)
Mark protocol stages (start, stop, ACK)
Explain special conditions

When the lanes match the examples, export PNG or SVG from the editor and compare the bit order against the figure before you put the image in a document.

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