DWFV

A simple digital waveform viewer with vi-like key bindings.

$ dwfv sample.vcd

The tool takes a Value Change Dump (VCD) file (as defined by IEEE Standard
1364-1995) as input and displays the waveforms using
tui-rs.

The backend API which facilitates the manipulation of digital signals in Rust
is also exposed and can be used independently of the TUI.

Installation

$ cargo install dwfv

From sources:

$ cargo install --path .

Key Bindings

Global

• q: quit

Cursor movement

• h/Left: move cursor left
• j/Down: move cursor down
• k/Up: move cursor up
• l/Right: move cursor right
• w: jump forward to the next rising edge
• e: jump forward to the next falling edge
• b: jump backward to the previous rising edge
• 0: jump to timestamp 0
• ^/Home: jump to the first event
• $/End: jump to the last event
• gg: jump to first signal
• G: jump to last signal

Frame

• zi/+: zoom in
• zo/-: zoom out
• zc/=: zoom fit
• zz: center cursor on screen

Editing

• o: edit layout
• dd/Delete: delete the selected signal
• yy: copy the selected signal
• p: paste the clipboard after cursor
• P: paste the clipboard before cursor
• u: undo
• r: redo
• c: show clipboard

Search

• f: search for event in the selected signal
• /: search for pattern in the signal’s names
• n: repeat search forward
• N: repeat search backward

Visual mode

• v: start visual mode
• <enter>: zoom fit the selected time frame

Mouse

• Left click: move cursor
• Right click: zoom out
• Wheel up: zoom in
• Wheel down: zoom out
• Hold/release left click: zoom fit the selected time frame

Command-Line Interface

Show some stats about the VCD file

$ dwfv examples/sample.vcd --stats
test
  ! (value) - width: 8, edges: 37, from: 0s, to: 1010s
  " (clk) - width: 1, edges: 102, from: 0s, to: 1010s
  # (reset) - width: 1, edges: 5, from: 0s, to: 620s
  c1
    " (clk) - width: 1, edges: 102, from: 0s, to: 1010s
    # (reset) - width: 1, edges: 5, from: 0s, to: 620s
    $ (out) - width: 8, edges: 37, from: 0s, to: 1010s

Display values of the signals at a given time

$ dwfv sample.vcd --at 1337
test
  ! (value) = h14
  " (clk) -> h1
  # (reset) = h0
  c1
    " (clk) -> h1
    # (reset) = h0
    $ (out) = h14

Search in the waveforms

Events in the waveforms can be searched using the ‘—when’ option. Examples:

• Searching when the value signal is equal to 2:

$ dwfv sample.vcd --when '$! = 2'
310s-330s
650s-670s
$ dwfv sample.vcd --when '$! equals h2'
310s-330s
650s-670s

• Searching when the value signal transitions to 4:

$ dwfv sample.vcd --when '$! <- 4'
350s
690s
$ dwfv sample.vcd --when '$! becomes b100'
350s
690s

• Searching when the value signal transitions to 4 after 400s:

$ dwfv sample.vcd --when '$! <- 4 and after 400'
690s

• Searching when the value signal transitions to 4 before 400s:

$ dwfv sample.vcd --when '$! <- 4 and before 400'
350s

LICENSE

MIT