wavy - a tool to convert ASCII art into logic trace images

Overview

The wavy tool is a lightweight program to convert simple ASCII art logic trace representations into a PNG. It was written because it has very light dependencies and can be used on any platform Go supports.

Getting started

Build from source:

$ go build wavy.go

The wavy program transforms .wvy files into .PNG images. For example, in the source repository, examples/hello.wvy looks like this:

+0 clk
+1,.25 aclk

zzzzzxxx^^^^______zz a
xx_^_^_^_^_^_^_^_^xx b
__/^^^\_____________ c
xx<-><->xxx<->xxxxxx d NOP,ACK,SYN

You can invoke ./wavy against it as follows:

$ ./wavy --input=examples/hello.wvy --output=hello.png

The generated hello.png looks like this:

Syntax

Summary of the syntax:

• blank lines are rendered as half-line empty spaces
• lines that start with “+” are interpreted as clocks and end with the clk symbol name
  • +0 is interpreted as the fastest clock in the trace
  • +1 is interpreted as a clock that has half the frequency as +0
  • +n is interpreted as a clock that has 1/(n+1) the frequency as +0
  • if this frequency indicator includes a suffix of ,D D is a phase difference for the clock relative to the default.
• non empty lines not covered by the clock syntax have the following form, with one exception for coded signals. That is, a signal trace followed by a signal name.
  • signal elements are generally considered transitions from something to something that line up with positive and negative edges of the +0 clock signal
    • z = high impedance (no output, potentially an input)
    • x = undefined (not assigned by logic, yet)
    • ^ = signal (goes/remains) high
    • _ = signal (goes/remains) low
    • / = signal transitions to high via a ramp
    • \ = signal transitions to low via a ramp
    • <---> = an interpreted signal
  • signals <-...-> can be substituted in sequence with comma separated symbols appended after the signal name

TODO

• add some support for converting numerical values (hex) into symbols to make traces more readable. Thinking of using a translate filter file like the one gtkwave supports.

License info

The wavy program is distributed with the same BSD 3-clause license as that used by golang itself.

Reporting bugs and feature requests

The wavy has been developed purely out of self-interest and a curiosity for maintaing some project documentation. Should you find a bug or want to suggest a feature addition, please use the bug tracker.